Rise of the Ottoman Empire

The Foundation and Rise of the Ottoman Empire (1299 – 29 May 1453) is the period that started with the weakening of the Seljuq Sultanate of Rûm in the very early 14th century and ended with the Byzantine Empire decline and the Fall of Constantinople on May 29, 1453.

The rise of the Ottomans correlates with the decline of the Byzantine Empire, which generated the shift in power from a singular Christian European society to an Islamic influence. The beginning of this period was characterized by the Byzantine-Ottoman wars which lasted for a century and a half. During this period, the Ottoman Empire gained control of both Anatolia and the Balkans.

Immediately after the establishment of the Anatolian beyliks, some Turkic principalities united with the Ottomans against the Byzantine Empire. The rise period witnessed Sultanate of Rûm's defeat against the Mongols in the 14th century and was followed by the Growth of the Ottoman Empire — a period referred as Pax Ottomana, the economic and social stability attained in the conquered provinces of the Ottoman Empire, by some historians.

Anatolia before the rule of the Ottomans
The origins of the Ottomans can be traced back to the late 11th century when a few small Muslim emirates of Turkic origins and Ghazi (Warrior for the cause of Islam) nature—called Beyliks—started to be founded in different parts of Anatolia. Their main role was to defend Seljuq border areas with the Byzantine Empire —a role reinforced by the migration of many Turks to Asia Minor. However, in 1073 and following the victory of the Seljuq Sultanate of Rûm over the Byzantines at the Battle of Manzikert, Beyliks sought an opportunity to override the Seljuq authority and declare their own sovereignty openly.

While the Byzantine Empire was to continue for nearly another four centuries, and the Crusades would contest the issue for some time, the victory at Manzikert signalled the beginning of Turkic ascendancy in Anatolia. The subsequent weakening of the Byzantine Empire and the political rivalry between the Seljuq Sultanate of Rûm and the Fatimids in Egypt and southern Syria were the main factors that helped the Beyliks take advantage of the situation and unite their principalities.

Among those principalities was a principality called Söğüt, founded and led by Ertuğrul, which settled in the river valley of Sakarya. When Ertuğrul died in 1281, his son Osman became his successor. Shortly thereafter, Osman declared himself a Sultan and established the Ottoman Dynasty, becoming the first Sultan of the Ottoman Empire in 1299.

Osman I (1299–1326)
The reign of Osman I marks the official beginning of the rule of the Ottoman dynasty which lasted for six centuries. In 1265 the Byzantine city Thebasion, Söğüt in Turkish, fell to Osman I. It was but the first of many cities and villages captured by the Ottoman Turks during the 1300s and 1310s. Osman also conquered some of the nearby Turkish emirates and tribes. During the late 1310s Osman I laid siege to several important Byzantine forts.

Yenişehir was captured and with it as a base the Turks could lay siege to Prousas (Bursa) and Nicaea (Iznik), the largest Byzantine cities in Anatolia. Bursa fell in 1326, just before Osman's death.


 * See also: Battle of Bapheus, Siege of Bursa

Orhan (1326–1362)
The son of Osman, Orhan I, conquered Nicaea in 1331 and Nicomedia in 1337 and established the capital in Bursa. During Orhan's reign the empire was organized as a state with a new currency, government and a modernized army.

Orhan married Theodora, the daughter of Byzantine prince John VI Cantacuzenus. In 1346 Orhan openly supported John VI in the overthrowing of the emperor John V Palaeologus. When John VI became co-emperor (1347–1354) he allowed Orhan to raid the peninsula of Gallipoli which gained the Ottomans their first stronghold in Europe. Orhan decided to pursue war against Europe, Anatolian Turks were settled in and around Gallipoli to secure it as a springboard for military operations in Thrace against the Byzantines and Bulgarians. Most of eastern Thrace was overrun by Ottoman forces within a decade and permanently brought under Orhan's control by means of heavy colonization. The initial Thracian conquests placed the Ottomans strategically astride all of the major overland communication routes linking Constantinople to the Balkans’ frontiers, facilitating their expanded military operations. ln addition, control of the highways in Thrace isolated Byzantium from direct overland contact with any of its potential allies in the Balkans or in Western Europe. Byzantine Emperor John V was forced to sign an unfavorable treaty with Orhan in 1356 that recognized his Thracian losses.


 * See also: Battle of Pelekanon, Siege of Nicaea, Siege of Nicomedia

Murad I (1362–1389)
Soon after Orhan's death in 1362, Murad I become the Sultan.

Adrianople, 1365–1369
Murad's first major offensive was the Battle of Adrianople. Adrianople was the most important Byzantine military, administrative, and economic center in Thrace. By transferring his capital from Bursa, in Anatolia, to that newly won city, which he renamed Edirne, Murad signaled his intentions to continue Ottoman expansion in Europe.

Before the fall of Adrianople, most Europeans regarded the Ottoman presence in Thrace as merely the latest unpleasant episode in a long string of chaotic events in the southern Balkans. After Murad designated Edirne as his capital, they realized that the Ottomans intended to remain in Europe.

The Balkan states immediately scared by the Ottomans' conquests in Thrace -Byzantium, Bulgaria, and Serbia— were ill-prepared to deal with the threat. Byzantium's territory was fragmented mostly among the capital at Constantinople and its Thracian environs, the city of Thessaloniki and its immediate surroundings, and the Despotate of the Morea in the Peloponnese. Contact between Constantinople and the two other regions was possible only by means of a tenuous sea route through the Dardanelles kept open by the Italian maritime powers of Venice and Genoa. The weakened Byzantine Empire no longer possessed the resources to defeat Murad on its own, and concerted action on the part of the Byzantines, often divided by civil war, was impossible. The survival of Constantinople itself depended on its legendary defensive walls, the lack of an Ottoman navy, and the willingness of Murad to honor provisions in the 1356 treaty permitting the city to be provisioned.

Bulgaria under Tsar Ivan Aleksandur was in decline. To consolidate his authority over as much territory as possible, he divided the state into three appanages held by his sons. Bulgaria's cohesion was shattered further in the 1350s by a rivalry between the holder of Vidin, Ivan Stratsimir, Ivan Aleksandur's sole surviving son by his first wife, and Ivan Shishman, the product of Aleksandur's second marriage and the tsar's designated successor. In addition to internal problems, Bulgaria was further crippled by Hungarian attack. In 1365 Hungarian King Louis I invaded and seized Vidin province, whose ruler Stratsimir was taken captive. Despite the concurrent loss of most Bulgarian Thracian holdings to Murad, Ivan Aleksandur became fixated on the Hungarians in Vidin. He formed a coalition against them with Dobrudzhan ruler Dobrotitsa and Voievod Vladislav I Vlaicu of Wallachia. Although the Hungarians were repulsed and Stratsimir was restored to his throne, Bulgaria emerged more intensely divided than previously. Stratsimir proclaimed himself tsar of an "Empire" of Vidin in 1370, and Dobrotitsa received de facto recognition as independent despot in Dobrudzha. Bulgaria's efforts were squandered to little domestic purpose and against the wrong enemy.

Given Serbia's preeminence in the Balkans under Car Stefan Dušan, its rapid dissolution following his death in 1355 was dramatic. The powerful regional Serb nobles demonstrated little respect for his successor, Stefan Uroš V. Young, weak, and perhaps mentally handicapped, Uroš was incapable of ruling as his father had. The separatist-minded bojars were quick to take advantage of the situation, and Serbia fragmented.

First to throw off Serbian control were the Greek provinces of Thessaly and Epiros as well as Dušan's former Albanian holdings. A series of small independent principalities arose in western and southern Macedonia, while the Hungarians encroached deeper into Serb lands in the north. Uros held only the core Serbian lands, whose nobles, although more powerful than their prince, generally remained loyal. These core lands consisted of: The western lands, including Montenegro (Zeta); the southern lands, held by Jovan Uglješa in Serres, encompassing all of eastern Macedonia; and the central Serbian lands, stretching from the Danube south into central Macedonia, coruled by Uroš and the powerful noble Vukasin Mrnjavcevic, who held Prilep in Macedonia. Far from preserving Serb unity, Uroš's loosely amalgamated domains were wracked by constant civil war among the regional nobles, leaving Serbia vulnerable to the rising Ottoman threat. Murad I did rise to the power of the Ottoman Empire in 1362.

Gallipoli, 1366
By 1370 Murad controlled most of Thrace, bringing him into direct contact with Bulgaria and the southeastern Serbian lands ruled by Uglješa. Uglješa, the most powerful Serb regional ruler, unsuccessfully attempted to forge an anti-Ottoman alliance of Balkan states in 1371. Byzantium, vulnerable to the Turks because of its food supply situation, refused to cooperate. Bulgaria, following Ivan Aleksandur's death early that year, lay officially divided into the "Empire" of Vidin, ruled by Stratsimir (1370–96), and Aleksandur's direct successor Tsar Ivan Shishman (1371–95), who ruled central Bulgaria from Turnovo. Young, his hold on the throne unsteady, threatened by Stratsimir, and probably pressured by the Turks, Shishman could not afford to participate in Uglješa's scheme. Of the regional Serb bojars, only Vukašin, protector of Uroš and Uglješa's brother, joined in the effort. The others either failed to recognize the Ottoman danger or refused to participate lest competitors attacked while they were in the field.

Maritsa, 1371


The Battle of Maritsa took place at the Maritsa River near the village of Chernomen on September 26, 1371 with sultan Murad's lieutenant Lala Shahin Pasha and the Serbs numbering some 70,000 men under the command of the Serbian king of Prilep Vukašin Mrnjavčević and his brother despot Uglješa. Despot Uglješa wanted to make a surprise attack in their capital city, Edirne, while Murad I was in Asia Minor. The Ottoman army was much smaller, but due to superior tactics (night raid on the allied camp), Şâhin Paşa was able to defeat the Christian army and kill King Vukašin and despot Uglješa. Macedonia and parts of Greece fell under Ottoman power after this battle. Both Uglješa and Vukašin perished in the carnage. So overwhelming was the Ottoman victory that the Turks referred to the battle as the Rout (or Destruction) of the Serbs.

What little unity Serbia possessed collapsed after the catastrophe at Ormenion. Uroš died before the year was out, ending the Nemanjić dynasty, and large areas of central Serbia broke away as independent principalities, reducing it to half of its former size. No future ruler ever again officially held the office of car, and no single bojar enjoyed enough power or respect to gain recognition as a unifying leader. Vukasin's son Marko, who survived the slaughter, proclaimed himself Serbian "king" (kralj) but was unable to make good on his claim outside of his lands around Prilep in central Macedonia. Serbia slipped into accelerated fragmentation and internecine warfare among the proliferating regional princes.

In the aftermath of the Ormenion battle, Ottoman raids into Serbia and Bulgaria intensified. The enormity of the victory and the incessant raids into his lands convinced Turnovo Bulgarian Tsar Shishman of the necessity for coming to terms with the Ottomans. By 1376 at the latest, Shishman accepted vassal status under Murad and sent his sister as the sultan's "wife" to the harem at Edirne. The arrangement did not prevent Ottoman raiders from continuing to plunder inside of Shishman's borders. As for Byzantium, Emperor John V definitively accepted Ottoman vassalage soon after the battle, opening the door to Murad's direct interference in Byzantine domestic politics.

The Bulgarians and Serbs enjoyed a brief respite during the 1370s and into the 1380s when matters in Anatolia and increased meddling in Byzantium's political affairs kept Murad preoccupied. In Serbia, the lull permitted the northern Serb ‘’bojar’’ Prince Lazar Hrebeljanovic (1371-89), with the support of powerful Bulgarian and Montenegrin nobles and the backing of the Serbian Orthodox Patriarchate of Pec, to consolidate control over much of the core Serbian lands. Most of the Serb regional rulers in Macedonia, including Marko, accepted vassalage under Murad to preserve their positions, and many of them led Serb forces in the sultan's army operating in Anatolia against his Turkish rivals.

Dubravnica, 1381
By the mid-1380s Murad's attention once again focused on the Balkans. With his Bulgarian vassal Shishman preoccupied by a war with Wallachian Voievod Dan I of Wallachia (ca. 1383-86), in 1385 Murad took Sofia, the last remaining Bulgarian possession south of the Balkan Mountains, opening the way toward strategically located Niš, the northern terminus of the important Vardar-Morava highway.

Saurian Field, 1385
Savra field battle was fought on 18 September 1385 between Ottoman and Serbian forces. The Ottomans were victorious and most of the local Serbian and Albanian lords became vassals.

Plocnik, 1386
Murad captured Nis in 1386, perhaps forcing Lazar of Serbia to accept Ottoman vassalage soon afterward. While he pushed deeper into the north—central Balkans, Murad also had forces moving west along the ‘’Via Ingatia’’ into Macedonia, forcing vassal status on regional rulers who until that time had escaped that fate. One contingent reached the Albanian Adriatic coast in 1385. Another took and occupied Thessaloniki in 1387. The danger to the continued independence of the Balkan Christian states grew alarmingly apparent.

When Anatolian affairs forced Murad to leave the Balkans in 1387, his Serbian and Bulgarian vassals attempted to sever their ties to him. Lazar formed a coalition with Tvrtko I of Bosnia and Stratsimir of Vidin. After he refused an Ottoman demand that he live up to his vassal obligations, troops were dispatched against him. Lazar and Tvrtko met the Turks and defeated them at Plocnik, west of Nis. The victory by his fellow Christian princes encouraged Shishman to shed Ottoman vassalage and reassert Bulgarian independence.

Bileća, 1388
Murad returned from Anatolia in 1388 and launched a lightning campaign against the Bulgarian rulers Shishman and Stratsimir, who swiftly were forced into vassal submission. He then demanded that Lazar proclaim his vassalage and pay tribute. Confident because of the victory at Plocnik, the Serbian prince refused and turned to Tvrtko of Bosnia and Vuk Brankovic, his son-in-law and independent ruler of northern Macedonia and Kosovo, for aid against the certain Ottoman retaliatory offensive.

Kosovo, 1389
Murad's expected assault materialized in 1389. The sultan personally led the largest Ottoman force mustered in the Balkans to that time, which included Christian contingents furnished by Bulgarian, Serbian, Albanian, and Macedonian vassals, Kralj Marko of Prilep among them. Likewise, Lazar himself commanded the coalition army composed of troops of his loyal Serb bajars, Brankovic's Kosovar and northern Macedonian forces, a Bosnian contingent, and some allied Hungarian and Albanian units. The protagonists met at Kosovo Polje (the "Field of the Blackbirds") on 15 June 1389. Sources differ on the size of the forces involved, but apparently Murad faced 100,000 Europeans with no more than 60,000 at best. The battle went poorly for the Ottomans at first, but a last minute defection by the forces of Brankovic altered the course of the battle in their favor. Murad was killed, but his son Prince Bayezid took command and led the Ottomans to victory. Some sources claim that it was Murad who led his men to victory, but that he was assassinated shortly afterward. Either way, the battle destroyed the last organized resistance in the Balkans south of the Danube. The victory opened northern Serbia to later Ottoman conquest, and left Hungary as the only important opponent in Southeastern Europe.

The battle of Kosovo was an important victory for the Ottomans. While the Ottomans could count on an Anatolian reserve to replace their losses, the Serbs, who had mustered all of their able-bodied troops for the battle, were left irreparably weakened. In the three years following the battle, Ottoman raids forced one militarily ineffective Serb regional ruler after another to accept vassalage to Bayezid. Lazar's young and weak successor Stefan Lazarevic (1389–1427) concluded a vassal agreement with Bayezid in 1390 to counter Hungarian moves into northern Serbia, while Vuk Brankovic, the last independent Serb prince, held out until 1392.

Beyazid I (1389–1402)
Beyazid I ( so called Yıldırım, "the Thunderbolt") succeeded to the sultanship upon the assassination of his father Murad. In a rage over the attack, he ordered all Serbian captives killed; Beyazid became known as Yıldırım, the lightning bolt, for his temperament.

Bayezid, "the Thunderbolt", lost little time in expanding Ottoman Balkan conquests. He followed up on his victory by raiding throughout Serbia and southern Albania, forcing most of the local princes into vassalage. Both to secure the southern stretch of the Vardar-Morava highway and to establish a firm base for permanent expansion westward to the Adriatic coast, Bayezid settled large numbers of ‘’yürüks’’ along the Vardar River valley in Macedonia.

The appearance of Turk raiders at Hungary's southern borders awakened Hungarian King Sigismund of Luxemburg (1387–1437) to the danger that the Ottomans posed to his kingdom, and he sought out Balkan allies for a new anti-Ottoman coalition.

By early 1393 Turnovo Bulgaria's Ivan Shishman, hoping to throw off his onerous vassalage, was in secret negotiations with Sigismund, along with Wallachian Voievod Mircea the Old (1386–1418) and, possibly, Vidin's Ivan Stratsimir. Bayezid got wind of the talks and launched a devastating campaign against Shishman. Turnovo was captured after a lengthy siege, and Shishman fled to Nikopol. After that town fell to Bayezid, Shishman was captured and beheaded. All of his lands were annexed outright by the sultan, and Stratsimir, whose Vidin holdings had escaped Bayezid's wrath, was forced to reaffirm his vassalage.

Having dealt harshly and effectively with his disloyal Bulgarian vassals, Bayezid then turned his attention south to Thessaly and the Morea, whose Greek lords had accepted Ottoman vassalage in the 1380s. Their incessant bickering among themselves, especially those of the Greek Morean magnates, required Bayezid's intervention. He summoned a meeting of all his Balkan vassals at Serres in 1394 to settle these and other outstanding matters. Among the sultan's attending vassals were the Thessalian and Morean nobles, Byzantine Emperor Manuel II Palaiologos (1391–1425), and Serbian Prince Lazarevic. At the meeting, Bayezid acquired possession of all disputed territories, and all of the attendees were required to reaffirm their vassal status.

When the Moreans later reneged on their Serres agreement with Bayezid, the angered Ottoman ruler blockaded the Morean despot's imperial brother Manuel II in Constantinople and then marched southward and annexed Thessaly. The Duchy of Athens accepted Ottoman overlordship when Turkish forces appeared on its border. Although a massive Ottoman punitive raid into the Peloponnese in 1395 netted much booty, events in the Balkans’ northeast saved Morea from further direct attack at the time.

While Bayezid was occupied in Greece, Mircea of Wallachia conducted a series of raids across the Danube into Ottoman territory. In retaliation, Bayezid's forces, which included Serb vassal troops led by Lazarevic and Kralj Marko, struck into Wallachia in 1395 but were defeated at Rovine, where Marko was killed. The victory saved Wallachia from Turkish occupation, but Mircea accepted vassalage under Bayezid to avert further Ottoman intervention. The sultan took consolation for his less than victorious efforts in annexing Dobrudzha and in supporting a pretender, Vlad I (1395–97), to the Wallachian throne. Two years of civil war ensued before Mircea regained complete control of the principality.

Nicopolis


In 1396 Hungarian King Sigismund finally pulled together a crusade against the Ottomans. The crusader army was composed primarily of Hungarian and French knights, but included some Wallachian troops. Though nominally led by Sigismund, it lacked command cohesion. The crusaders crossed the Danube, marched through Vidin, and arrived at Nikopol, where they met the Turks. The headstrong French knights refused to follow Sigismund's battle plans, resulting in their crushing defeat. Because Stratsimir had permitted the crusaders to pass through Vidin, Bayezid invaded his lands, took him prisoner, and annexed his territories. With Vidin's fall, Bulgaria ceased to exist, becoming the first major Balkan Christian state to disappear completely by direct Ottoman conquest.

Following Nikopol, Bayezid contented himself with raiding Hungary, Wallachia, and Bosnia. He conquered most of Albania and forced the remaining northern Albanian lords into vassalage. A new, halfhearted siege of Constantinople was undertaken but lifted in 1397 after Emperor Manuel II, Bayezid's vassal, agreed that the sultan should confirm all future Byzantine emperors. Soon thereafter Bayezid was called back to Anatolia to deal with continuing problems with the Ottomans’ Turkish rivals and never returned to the Balkans.

Ankara, 1402
Bayezid took with him an army composed primarily of Balkan vassal troops, including Serbs led by Lazarevic. He soon faced an invasion of Anatolia by the Central Asian ruler Timur Lenk. Around 1400, Timur entered the Middle East. Timur Lenk pillaged a few villages in eastern Anatolia and commenced the conflict with the Ottoman Empire. In August, 1400, Timur and his horde burned the town of Sivas to the ground and advanced into the mainland. Their armies met outside of Ankara, at the Battle of Ankara, in 1402. The Ottomans were routed and Bayezid was taken prisoner, later dying in captivity. The Ottomans were reduced to Timurid vassals. A civil war, lasting from 1402 to 1413, broke out among Bayezid's surviving sons. Known in Ottoman history as the Interregnum, that struggle temporarily halted active Ottoman expansion in the Balkans.

Ottoman Interregnum (1402–1413)
After the defeat at Ankara followed a time of total chaos in the Empire. Mongols roamed free in Anatolia and the political power of the sultan was broken. After Beyazid was captured, his remaining sons, Suleiman Çelebi, İsa Çelebi, Mehmed Çelebi, and Musa Çelebi fought each other in what became known as the Ottoman Interregnum.

The Ottoman Interregnum brought a brief period of semi-independence to the vassal Christian Balkan states. Suleyman, one of the late sultan's sons, held the Ottoman capital at Edirne and proclaimed himself ruler, but his brothers refused to recognize him. He then concluded alliances with Byzantium, to which Thessaloniki was returned, and with Venice in 1403 to bolster his position. Suleyman's imperious character, however, turned his Balkan vassals against him. In 1410 he was defeated and killed by his brother Musa, who won the Ottoman Balkans with the support of Byzantine Emperor Manuel II, Serbian Despot Stefan Lazarevic, Wallachian Voievod Mircea, and the two last Bulgarian rulers’ sons. Musa then was confronted for sole control of the Ottoman throne by his younger brother Mehmed, who had freed himself of Mongol vassalage and held Ottoman Anatolia.

Concerned over the growing independence of his Balkan Christian vassals, Musa turned on them. Unfortunately, he alienated the Islamic bureaucratic and commercial classes in his Balkan lands by continually favoring the lower social elements to gain wide popular support. Alarmed, the Balkan Christian vassal rulers turned to Mehmed, as did the chief Ottoman military, religious, and commercial leaders. In 1412 Mehmed invaded the Balkans, took Sofia and Nis, and joined forces with Lazarevicys Serbs. The following year Mehmed decisively defeated Musa outside of Sofia. Musa was killed, and Mehmed I (1413–21) emerged as the sole ruler of a reunited Ottoman state. Mehmed I faced a delicate political situation in the Balkans. His Serbian, Wallachian, and Byzantine vassals virtually were independent. The Albanian tribes were uniting into a single state, and Bosnia remained completely independent, as did Moldavia. Hungary retained territorial ambitions in the Balkans, and Venice held numerous Balkan coastal possessions. Prior to Bayezid's death, Ottoman control of the Balkans appeared a certainty. At the end of the Interregnum, that certainty seemed open to question.

Mehmed I (1413–1421)
When Mehmed Çelebi stood as victor in 1413 he crowned himself in Edirne (Adrianople) as Mehmed I. His was the duty to restore the Ottoman Empire to its former glory. The Empire had suffered hard from the interregnum; the Mongols were still at large in the east, even though Timur had died in 1405; many of the Christian kingdoms of the Balkans had broken free of Ottoman control; and the land, especially Anatolia, had suffered hard from the war.

Mehmed moved the capital from Bursa to Adrianople. He faced a delicate political situation in the Balkans. His Bulgarian, Serbian, Wallachian, and Byzantine vassals were virtually independent. The Albanian tribes were uniting into a single state, and Bosnia remained completely independent, as did Moldavia. Hungary retained territorial ambitions in the Balkans, and Venice held numerous Balkan coastal possessions. Prior to Bayezid's death, Ottoman control of the Balkans appeared a certainty. At the end of the interregnum, that certainty seemed open to question.

Mehmed generally resorted to diplomacy rather than militancy in dealing with the situation. While he did conduct raiding expeditions into neighboring European lands, which returned much of Albania to Ottoman control and forced Bosnian King-Ban Tvrtko II Kotromanić (1404–09, 1421–45), along with many Bosnian regional nobles, to accept formal Ottoman vassalage, Mehmed conducted only one actual war with the Europeans — a short and indecisive conflict with Venice.

The new sultan had grave domestic problems. Musa's former policies sparked discontent among the Ottoman Balkans’ lower classes. In 1416 a popular revolt of Muslims and Christians broke out in Dobruja, led by Musa's former confidant, the scholar-mystic Şeyh Bedreddin, and supported by Wallachian voivod Mircea I. Bedreddin preached such concepts as merging Islam, Christianity, and Judaism into a single faith and the social betterment of free peasants and nomads at the expense of the Ottoman bureaucratic and professional classes. Mehmed crushed the revolt and Bedreddin died. Mircea then occupied Dobruja, but Mehmed wrested the region back in 1419, capturing the Danubian fort of Ciurgiu and forcing Wallachia back into vassalage.

Mehmed spent the rest of his reign reorganizing Ottoman state structures disrupted by the interregnum. When Mehmed died in 1421, one of his sons, Murad, became sultan.

Murad II (1421–1451)
Murad II spent his early years on the throne disposing of rivals and rebellions, most notably the revolts of the Serbs. He also had problems at home. He subdued the rebels of his uncle Mustafa Çelebi and brother Küçük Mustafa.

Constantinople, 1423
In 1423 he paid a short visit to Constantinople, laid siege on it for a couple of months and forced the Byzantines to pay additional tribute.

In 1423 the first regular war against Venice began. During Murad's siege of Constantinople, the Byzantine Emperor's control over the Greek city-states weakened.

Thessalonika, 1430
On the request of its inhabitants, Venetian troops took control of the city of Salonika (Thessaloniki). The Ottoman army that laid siege to the city knew nothing of the transfer of power, and a number of Venetian soldiers were killed by Ottoman troops, believing them to be Greeks. Murad II had been on peaceful terms with Venice, so the Venetians deemed the act unacceptable and declared full war.

Murad acted swiftly, besieging Constantinople and sending his armies to Salonika. The Venetians had gained reinforcements by sea but when the Ottomans stormed the city the outcome was forgone and the Venetians fled to their ships. But when the Turks entered and began plundering the city the Venetian fleet started bombarding the city from the sea-side. The Ottomans fled and the fleet was able to hold off the Ottomans until new Venetian reinforcements arrived to recapture the city. The outcome of the Battle of Salonika was a setback for Murad and Serbia and Hungary allied themselves with Venice. Pope Martin V encouraged other Christian states to join the war against the Ottomans, though only Austria ever sent any troops to the Balkans.

The war in the Balkans began as the Ottoman army moved to recapture Wallachia, which the Ottomans had lost to Mircea I of Wallachia during the Interregnum and that now was a Hungarian vassal state. As the Ottoman army entered Wallachia, the Serbs started attacking Bulgaria and, at the same time, urged by the Pope, the Anatolian emirate Karamanid attacked the Empire from the back. Murad had to split his army. The main force went to defend Sofia and the reserves had to be called to Anatolia. The remaining troops in Wallachia were crushed by the Hungarian army that was now moving south into Bulgaria where the Serbian and Ottoman armies battled each other. The Serbs were defeated and the Ottomans turned to face the Hungarians who fled back into Wallachia when they realized they were unable to attack the Ottomans from the back. Murad fortified his borders against Serbia and Hungaria but did not try to retake Wallachia, instead he sent his armies to Anatolia where they defeated Karaman in 1428.

In 1430 a large Ottoman fleet attacked Salonika by surprise. The Venetians signed a peace treaty in 1432. The treaty gave the Ottomans the city of Salonika and the surrounding land. The war between Serbia and Hungary and the Ottoman Empire had come to a standstill in 1441 when the Holy Roman Empire, Poland, Albania, and the Jandarid and Karamanid emirates (in violation of the peace treaty) intervened against the Ottomans. Niš and Sofia fell to the Christians in 1443 and the year after the Empire suffered a major defeat in the Battle of Jalowaz. July 12, 1444 Murad signed a treaty that officially gave Wallachia and the Bulgarian province of Varna to Hungary, western Bulgaria (including Sofia) to Serbia and forced Murad to abdicate in favor of his twelve-year-old son Mehmed. Later the same year the Christians violated the peace treaty and attacked anew.

Varna, 1444
On November 11, 1444, Murad defeated the Polish–Hungarian army of Wladislaus III of Poland led by Janos Hunyadi at the Battle of Varna.

Murad was reinstated with the help of the Janissaries in 1446. Another peace treaty was signed in 1448 giving the Empire Wallachia and Bulgaria and a part of Albania. After the Balkan front was secured, Murad turned east and defeated Timur Lenk's son, Shah Rokh, and the emirates of Candar and Karaman in Anatolia.

Kosovo, 1448
At 1448, John Hunyadi saw the right moment to lead a campaign against the Ottoman Empire. After the Defeat of Varna (1444), he raised another army to attack the Ottomans. His strategy based on possible revolt of Balkan people and the surprise attack, also the assumption to destroy the main force of the Ottomans in a single battle. Hunyadi was totally immodest and led his forces without leaving any escort behind.

Murad died in the winter 1450–1451 in Edirne. Some have it that he was wounded in a battle against Skanderbeg's Albanian guerillas.

Many doubted the young Mehmed II when he became sultan (again) following his father's death.

Mehmed II (1451–1481)
Mehmed II (so called Fatih, the Conqueror) again came to the Ottoman throne following Murad's death in 1451. But by conquering and annexing the emirate of Karamanid (May–June, 1451) and by renewing the peace treaties with Venice (September 10) and Hungary (November 20) Mehmed II proved his skills both on the military and the political front and was soon accepted by the noble class of the Ottoman court.

Older and a good deal wiser, he made capturing Constantinople his first priority, believing that it would solidify his power over the high military and administrative officials who had caused him such problems during his earlier reign. Good reasons underlay his decision. So long as Constantinople remained in Christian hands, his enemies could use it as either a potential base for splitting the empire at its center or as an excuse for the Christian West's continued military efforts. Constantinople's location also made it the natural "middleman" center for both land and sea trade between the eastern Mediterranean and central Asia, possession of which would ensure immense wealth. Just as important, Constantinople was a fabled imperial city, and its capture and possession would bestow untold prestige on its conqueror, who would be seen by Muslims as a hero and by Muslims and Christians alike as a great and powerful emperor.

Mehmed spent two years preparing for his attempt on the Byzantine capital. He built a navy to cut the city off from outside help by sea; he purchased an arsenal of large cannons from the Hungarian gunsmith Urban; he sealed the Bosphorus north of the city by erecting a powerful fortress on its European shore to prevent succor arriving from the Black Sea; and he meticulously concentrated in Thrace every available military unit in his lands. A trade agreement with Venice prevented the Venetians from intervening on behalf of the Byzantines, and the rest of Western Europe unwittingly cooperated with Mehmed's plans by being totally absorbed in internecine wars and political rivalries.

Constantinople, 1453
When in 1451 the bankrupt Byzantines asked Mehmed to double the tribute for holding an Ottoman pretender for the throne, he used the request as a pretext for annulling all treaties with the Byzantine Empire. Nevertheless, when he proposed in 1452 to siege Constantinople most of the divan, and especially the Grand Vizier, Çandarlı Halil Pasha, was against it and criticized the Sultan for being too rash and overconfident in his abilities. On April 15, 1452, Mehmed ordered preparations to be made for the siege of Constantinople.

In April 1453, Mehmed laid siege to Constantinople. Although the city's defenders, led by Giovanni Giustiniani under Emperor Constantine XI Palaiologos's (1448–53) authority, put up a heroic defense, without the benefit of outside aid their efforts were doomed. The formerly impregnable land walls were breached after two months of constant pounding by Mehmed's heavy artillery. In the predawn hours of 29 May 1453, Mehmed ordered an all-out assault on the battered ramparts. After a brief but vicious melee at the walls in which Giustiniani was severely injured coupled with Ottoman troops breaching the walls through a sally port door left open, the Ottoman troops were able to breach the walls and rout the defenders. According to Christian sources, Emperor Constantine died bravely rushing into the oncoming Ottoman troops not to be seen again. However, according to Ottoman sources such as Tursun Beg he threw off his mantle and attempted to flee before being cut down by an injured Ottoman soldier. The Ottoman Army broke through and swept over the city. Constantinople, for a millennium considered by many Europeans the divinely ordained capital of the Christian Roman Empire, fell to Mehmed and was transformed into what many Muslims considered the divinely ordained capital of the Islamic Ottoman Empire. The fabled city's imperial legacy lived on. After the conquest, the sultan had his grand vizier Çandarlı Halil Pasha killed. His following four granviziers were of devshirme origin. During the growth of the Empire Turks seldom were appointed to the high positions.

Following the capture of Constantinople, Mehmed built the Topkapı Palace in 1462 and moved the Ottoman capital there from Adrianople. Mehmed had himself titled "Kaiser-i-Rum", or "Roman Caesar", and modelled the state after the old Byzantine Empire, thinking of himself as the successor to the Roman throne. Later, when he invaded Otranto, his goal was to capture Rome and reunite the Roman Empire for the first time since 751. Justinian's cathedral of Hagia Sophia was converted into an imperial mosque, as eventually were numerous other churches and monasteries. The rights of non-Muslim inhabitants were protected to ensure continuity and stability for commercial activities. Never fully recovered from the sack of 1204, and suffering from Byzantium's two centuries of near poverty, Constantinople by the time of Mehmed's conquest was but a hollow shell of its former self. Its population had dwindled, and much property was either abandoned or in a state of disrepair. The sultan immediately began to repopulate the city. Civic and private properties were offered to the public to entice much-needed skilled artisans, craftsmen, and traders of all religions and ethnicities back to the city. Newly conquered Constantinople rapidly grew into a multiethnic, multicultured, and bustling economic, political, and cultural center for the Ottoman state, whose distant frontiers guaranteed it peace, security, and prosperity.

Belgrade, 1456
Mehmed, now known as "the Conqueror", determined to centralize his empire. In the Balkans, he decided to eradicate the last vestiges of Byzantium in Morea and to eliminate the surviving Christian vassal princes elsewhere. In 1454 he commenced a series of military campaigns, lasting until 1463, aimed at establishing a solid military defense line along the Danube and the Adriatic against Hungary and Venice.

Serbia ranked first on Mehmed's agenda. After two years of campaigning, Mehmed acquired southern Serbia and the lucrative silver and gold mines of Novo Brdo. In 1456 a cowed Brankovié permitted Mehmed to march through his remaining lands and besiege the Hungarians in Belgrade. Mehmed's efforts to take the fortress city were checked by Hunyadi, who arrived with reinforcements at the last moment and forced Mehmed to retire. Soon afterward Brankovic died, and the usual Serbian succession problems reemerged. In the anarchy that erupted, Mehmed laid claim to the Serbian throne, based on his having a Serb stepmother, but continuing problems with Skanderbeg in Albania and the Byzantine despots in Morea prevented him from acting immediately on his claim.

The wily Albanian commander attempted to drive out the Ottoman garrisons stationed in Albania, and Mehmed dispatched a number of expeditions to push Skanderbeg's forces back into the mountains. While the sultan was thus occupied, the Morean despots, the brothers Demetrios Palaiologos of Mystras (1449–60) and Thomas Palaiologos of Patras (1449–60), fell into civil war. Demetrios was well disposed toward the Ottomans, while Thomas sought help from the pope and other Western rulers against both his brother and the Turks. Their conflict reduced Morea to anarchy.

Mehmed arrived in Greece in 1458 and annexed its northern regions. By early 1459 Athens was taken, and a year later Thomas was forced to flee Patras. Demetrios then handed over Mystras to Mehmed. With the fall of Morea in 1460, the Byzantine Empire ceased to exist. All of Greece, with the exception of the Venetian-controlled ports of Methoni, Koroni, and Pilos in Morea, lay under direct Ottoman authority.

A year before Morea fell, Mehmed had moved swiftly north and invaded Serbia one final time, making good on his claim to the Serbian throne. What lands that remained of vassal Serbia were occupied outright by Mehmed's forces. At the time Hungarian King Matthias Corvinus (1458–90), Hunyadi's son, was more interested in Central European affairs than in the Balkans, so he gave scant attention to events occurring south of his border. The Serbs’ last stand took place at Smederevo, which fell to Mehmed in June 1459. With its capture, the Serbian state completely disappeared. Only the city of Belgrade, still held by the Hungarians, lay beyond Mehmed"s control south of the Danube.

Following the conquests of Serbia and Greece, Skanderbeg's Albania continued to cause Mehmed problems. A truce was arranged with the troublesome Albanian in 1461 in time for Mehmed to deal with a Wallachian incursion into Bulgaria led by Voievod Vlad III Dracula, a renegade Ottoman vassal.

The following year Mehmed launched a campaign into Anatolia defeating the Jandarids in Sinope, and Armenia under Uzun Hasan before capturing the Empire of Trebizond on August 15, 1461.

In 1462 Mehmed invaded Wallachia and drove Dracula out. Instead of annexing the principality, he merely reduced it to vassal status under a new voievod.

Alarmed by the Ottomans’ consolidation of their Balkan holdings and expansion along the Adriatic coast, Venice encouraged the redoubtable Skanderbeg to break his truce with Mehmed in 1462. Bosnian King-Ban Stefan Tomasevic (1461–65), heartened by Skanderbegs renewed activities, renounced Ottoman suzerainty and accepted Hungarian protection. Herceg Stefan Vukcic (1455–66), lord of Hercegovina, which had separated from Bosnia in the 1440s, followed suit. Their actions elicited Mehmed's quick response. He invaded Albania in 1465 and forced Skanderbeg to sign a new truce. Next, he turned north and overran both Bosnia and Hercegovina. Bosnia was conquered outright but Hercegovina, with Hungarian assistance, staved off a similar fate for another eighteen years, until finally falling to the Turks in 1481.

One territory closely linked to the Serbs was Montenegro, a mountainous region to Serbia's southwest with a small coastline on the Adriatic. In the early 1450s it achieved independence from Brankovic's Serbia under the leadership of Stefan Crnojevic (ca. 1451-65), who enjoyed Venetian support. Assisted by his state's rugged terrain, Crnojevic turned back the raiders Mehmed sent against him during the 1450s, although a number of his regional tribal chieftains accepted Ottoman vassalage. After his death, his son Ivan Crnojevic (1465–90) swore vassalage to Mehmed in 1471, but that did not prevent the Ottomans from occupying large portions of his lands. When Ivan reneged on his tribute payments, Mehmed included an invasion of Montenegro in the massive assaults against Albania and its Venetian-held coastal cities that he dispatched in the years 1477 to 1479. Ivan was driven out and Mehmed annexed most of Montenegro.

Mehmed's moves in the western Balkans frightened the Venetians, who dreaded the continued Ottoman approach to the Adriatic coastline and its string of port cities. They patched together an anti-Ottoman alliance with Hungary and Skanderbeg in 1465. During the war, which lasted until 1479, Venice won possession of a number of Aegean islands but experienced terrifying Ottoman raids into its northeastern Italian holdings. Skanderbeg fought on until his death in 1468, after which Mehmed conquered Albania completely. Hungary held onto Belgrade by fending off Mehmed's second siege in 1464. Hungarian King Matthias injected a new player into the struggles with the Ottomans by securing an alliance with Moldavian Voievod Stefan the Great (1457–1504).

Moldavia traditionally maintained a policy of vassalage toward Poland to preserve its independence from Hungary. Its location in the extreme northeast, beyond both the Danube and Wallachia, spared it problems with the Ottomans until 1420, when Mehmed I first raided Moldavia after suppressing the Bedreddin rebellion. During the 1450s and 1440s the principality was wracked by civil wars, of which Sultan Murad II took advantage. As the state weakened, Voievod Peter Aron (1455–57) accepted Ottoman suzerainty and agreed to pay tribute, but, given Moldavia's distance from Ottoman borders, his acts were more symbolic than concrete.

Stefan the Great initially used the Ottoman vassalage inherited from his father as a tool against Hungary, Moldavia's traditional enemy. An exceptional military commander and organizer, Stefan captured the Danube commercial city of Kilia from Wallachia in 1465 and defeated a Hungarian invasion of his state two years later. As his successes both on the battlefield and in imposing his authority within Moldavia grew, Stefan ceased paying the annual tribute to the Ottomans, and his relationship with Mehmed II deteriorated. He invaded Wallachia in 1474 and ousted its prince, who was Mehmed's abject vassal. In response, Mehmed demanded that Stefan resume his tribute payments and turn over the city of Kilia as well. Stefan refused and soundly repulsed Mehmed's subsequent punitive invasion of Moldavia in early 1475.

Breadfield, 1479
The victorious zmievad realized that Mehmed would seek to avenge the defeat, so Stefan sought Hungarian aid by becoming Matthias Corvinus°s vassal. Mehmed personally led an invasion of Moldavia in 1476, and his forces plundered the country up to Suceava, Stefan's capital. Lack of provisions and an outbreak of cholera among the Ottoman troops, however, forced Mehmed to retire, and Stefan went on the offensive. He pushed into Wallachia and spent the next nine years fighting a heroic border war with the Ottomans. Stefan's efforts were the primary reason that the two Romanian Principalities maintained their independence and did not suffer the fate of the other Ottoman vassal states south of the Danube.

In 1480 Mehmed dispatched an army to Italy that marched against Rome to punish the pope for supporting Venice and assorted anti-Ottoman coalitions. The invasion force captured Otranto and was preparing to advance further inland when news of the sultan's death in 1481 halted their preparations.

When Mehmed died, the conquest of the Balkans essentially was complete.

After the Rise period
In the Ottoman history, 1453 is considered as the end of the Rise and the beginning of the Growth period. Stagnation, Decline and Dissolution periods followed the Growth.