Theodore Komnenos Doukas

Theodore Komnenos Doukas (Θεόδωρος Κομνηνός Δούκας, Theodōros Komnēnos Doukas; died ca. 1253), Latinized as Theodore Comnenus Ducas, was ruler of Epirus and Thessaly from 1215 to 1230 and of Thessalonica and most of the rest of Greek Macedonia and western Thrace from 1224 to 1230, as well as the real power behind the rule of his sons John and Demetrios over Thessalonica in 1237–46.

The scion of a distinguished aristocratic family related to the imperial Komnenos, Doukas, and Angelos dynasties, Theodore's life is unknown before the fall of Constantinople to the Fourth Crusade in 1204. After that, he served the Nicaean emperor Theodore I Laskaris for a few years, before being called to Epirus, where his bastard half-brother Michael I Komnenos Doukas had founded an independent principality. After Michael's death in 1215, Theodore sidelined the latter's underage and illegitimate son Michael II and assumed the governance of the Epirote state. Theodore continued his brother's policy of territorial expansion. Allied with Serbia, he expanded into Macedonia, threatening the Latin Kingdom of Thessalonica. The capture of the Latin Emperor Peter II of Courtenay in 1217 opened the way to the gradual envelopment of Thessalonica, culminating in the city's fall in 1224.

As ruler of Thessalonica, Theodore quickly declared himself emperor, challenging the Nicaean emperor John III Vatatzes's claims on the Byzantine imperial throne. In 1225, he advanced as far as the outskirts of Constantinople, but his attack against the seat of the much-reduced Latin Empire was delayed until 1230. In the event, Theodore diverted the army amassed to besiege Constantinople against Bulgaria, an ambivalent ally which threatened his northern flank. Theodore was defeated and captured at the Battle of Klokotnitsa, and spent the next seven years in captivity. In the meantime, he was succeeded by his brother Manuel. Manuel was unable to prevent the loss of Thrace, most of Macedonia, and Albania to the Bulgarian Tsar John II Asen, whose vassal Thessalonica now became, nor the splitting off of Epirus, where Michael II had seized control.

Theodore was released in 1237 when his daughter Irene married John Asen, and quickly managed to regain control of Thessalonica, ousting Manuel. Having been blinded during his captivity, he installed his eldest son John as emperor in his stead, but remained the de facto regent of the state. Manuel tried to regain Thessalonica with Nicaean support, but a negotiated settlement was reached which gave him Thessaly and left Thessalonica and its environs to Theodore and John. In 1241, John III Vatatzes invited Theodore to visit Nicaea. He was welcomed and treated with great honour, but was effectively detained there until the spring of next year, when Vatatzes marched on Thessalonica with Theodore in tow. Theodore was sent in to negotiate with his son and convince him to accept demotion to the rank of Despot and to recognize the suzerainty of Nicaea. In 1246 Vatatzes overthrew Theodore's unpopular younger son Demetrios and annexed Thessalonica. Theodore influenced his nephew Michael II to launch an attack on Thessalonica in 1251, but in 1252, Vatatzes campaigned against them and forced Michael to come to terms. Theodore was taken prisoner and sent into exile in Nicaea, where he died in ca. 1253.

Early life and career
Born about 1180/85, Theodore was a son of the sebastokrator John Doukas and of Zoe Doukaina. His paternal grandparents were Constantine Angelos and Theodora, a daughter of Emperor Alexios I Komnenos (reigned 1081–1118). Theodore's uncle, Andronikos, was the father of the emperors Isaac II Angelos (r. 1185–95 and 1203–04) and Alexios III Angelos (r. 1195–1203), who were thus Theodore's first cousins. As with most members of his family, he preferred to use the surname of "Doukas" or "Komnenos Doukas" (Κομνηνός ὁ Δούκας), while contemporaries variously called him "Doukas", "Komnenos", or even "Great Komnenos" (μέγας Κομνηνός), an appellation more usually found among the ruling family of the Empire of Trebizond. Theodore evidently preferred to be associated with the more successful dynasties of the Doukai and the Komnenoi, rather than the disastrous reign of the Angeloi; indeed the only medieval writers to call him "Angelos" were the later, hostile pro-Palaiologos historians Nikephoros Gregoras and Theodore Skoutariotes, while George Akropolites notably refers to him as "Komnenos" until his defeat at the Battle of Klokotnitsa in 1230 and as "Angelos" after.

His early life is obscure. After the Fourth Crusade captured Constantinople in 1204, he followed Theodore Laskaris to Asia Minor, where the latter soon founded the Empire of Nicaea. According to a letter of the Metropolitan of Corfu, George Bardanes, an apologist for Theodore, he provided valuable services to Laskaris, "taking many dangers for his sake and wresting many fortresses from the enemies and subduing them to Laskaris' rule", distinguishing himself through his valour and receiving many rewards from the Nicaean ruler. In ca. 1210, he was called by his half-brother Michael I Komnenos Doukas to join him in Epirus, where the latter had founded an independent Greek principality. The reason was that Michael's sole surviving son, the future Michael II Komnenos Doukas, was underage and illegitimate, while his other brothers were considered to lack the ability to rule. Laskaris willingly allowed Theodore to leave, but first he extracted an oath of allegiance to himself and his heirs. Already before his going to Epirus, Theodore had married Maria Petraliphaina, with whom he had four children. Traditionally, several scholars, such as Karl Hopf and Antoine Bon, have identified a certain Theodore, who appears as "lord of Argos" and the successor of Leo Sgouros in leading the resistance against the Crusaders in the northwestern Peloponnese, with Theodore Komnenos Doukas. This view has been questioned by Raymond-Joseph Loenertz who argues that there is no evidence for such an assumption, while it is well established that Theodore was in Nicaean service at the time.

Ruler of Epirus
From 1210 on, Michael I Komnenos Doukas was engaged in a campaign of expansion at the expense chiefly of the Latin Kingdom of Thessalonica to his east; after initial reverses, much of Thessaly was conquered. By 1214, Dyrrhachium and Corfu had been recovered as well. Michael was assassinated by a servant in late 1214 or in 1215. As Michael II was too young and illegitimate, Theodore had no trouble in sidelining the boy. According to the hagiography of St. Theodora of Arta, he sent the boy and his mother to exile in the Peloponnese for the duration of his reign. It must be noted that although modern historiography calls the Epirote state the "Despotate of Epirus", and often applies the title of Despot to both Michael I and Theodore, this is anachronistic, as neither of the two bore the title. It was Michael II who became the to first Epirote ruler be titled a Despot in the 1230s, while the designation of Epirus as a "despotate" first appears in Western sources in the 14th century.

Theodore was both capable and extremely ambitious. Notwithstanding his oath to Laskaris, he aspired to expand his state not only against Thessalonica, but to eventually recover Constantinople and revive the Byzantine Empire. To secure his northern flank, Theodore allied himself with Serbia and the Albanian clans. The Principality of Arbanon was already in the Epirote orbit under Michael I, and closer ties developed when its ruler, Demetrios died in 1215, leaving his principality to his widow, who promptly remarried in the next year to a Greek magnate, Gregory Kamonas. Against the Serbians, Theodore abandoned Michael I's attempt to pursue a northward expansion into Zeta, and instead pursued an alliance with the Serbian prince Stefan II Nemanjić (r. 1196–1228) that was directed towards keeping the Bulgarians in check. The ties between Epirus and Serbia were solidified by the marriage of Theodore's brother Manuel Komnenos Doukas to one of Stefan II's sisters in ca. 1216. Stefan II then sought to wed one of his sons—in all likelihood his eldest son and heir, Stefan Radoslav—to Michael I's second daughter Theodora, but the marriage fell through due to the refusal of the Archbishop of Ohrid Demetrios Chomatianos to sanction it, as Theodora was closely related to the bridegroom through his mother, Eudokia Angelina, a daughter of Alexios III Angelos. In 1217, Stefan II tried to circumvent this by suggesting himself as the groom to Theodora's half-sister Maria, but Chomatianos vetoed this proposal as well on similar grounds. In the event, Stefan Radoslav married Theodore's firstborn daughter Anna in winter 1219/20.

His position thus strengthened, Theodore expanded his territory into northern Macedonia, although it is possible that at least part of this region had already been captured by Michael I after the death of the local Bulgarian ruler Strez in 1214. It is unclear to what extent Theodore's expansion involved direct conflict with the Bulgarian Tsar Boril (r. 1207–18), but by 1217 he held Ohrid, Prilep, and most of the plain of Pelagonia, at least up to Strez's old capital at Prosek, and likely beyond, approaching the Strymon River. The capture of Ohrid, seat of the homonymous archbishopric, was particularly important. Indeed it was Theodore who sponsored the election of Chomatianos to the archiepiscopal throne in 1217. Chomatianos, a distinguished canonist, would repay that support with his steadfast championing of Epirote claims to the Byzantine imperial inheritance vis-à-vis the rival claims of Nicaea. Despite his close ties to Epirus, Stefan II Nemanjić exploited the Epirote–Nicaean rivalry to his advantage to secure autocephaly for the Serbian Church, which traditionally the latter had been under the jurisdiction of the Archbishop of Ohrid. Brushing aside Chomatianos' vehement objections, Stefan managed to have his brother Rastko, renamed Sava, consecrated by the Nicaea-based Patriarch of Constantinople, Manuel I Sarantenos, as autocephalous archbishop of Serbia in 1219. Despite the quarrels of the churchmen, however, relations between Theodore and Serbia remained cordial.

Theodore's drive into Macedonia disquieted another local strongman, Alexius Slav, ruler of Melnik. A sworn enemy of Boril, Alexius had been abandoned by his erstwhile ally, the Latin Emperor, Henry of Flanders (r. 1205–16), who in 1213 allied himself with Bulgaria. Facing a possible attack by Theodore as well, Alexius now preferred to mad=ke common cause with him, and married a niece of Theodore's wife. The Epirote successes in Macedonia disquieted the Latins, as they opened the way to another attack on Thessalonica. The Kingdom of Thessalonica had been much weakened after the death of its founder, Boniface of Montferrat, in 1207, and was then ruled by a regency for his underage son Demetrius (r. 1207–24). Interrupting a campaign against the Nicaeans in Asia Minor, Henry of Flanders hastened to Thessalonica. He took up contact with Boril and was preparing to march against Theodore when he suddenly died on 11 June 1216, probably of malaria, although poisoning by his second wife Maria of Bulgaria has also been suggested. The death of the warlike Henry, followed by Pope Innocent III, the instigator of the Fourth Crusade, a month later, was a major stroke of good fortune for Theodore as it removed two of his most eminent and capable opponents.

The barons of the Latin Empire then elected Peter II of Courtenay, a cousin of King Philip II Augustus of France, as the new Latin Emperor. Receiving news of his election, Peter assembled a small army of 160 knights and 5,500 foot and horse,and set out from France. After being crowned by Pope Honorius III in Rome, he set sail from Brindisi in April 1217. Peter landed at Dyrrhachium, which he had promised to conquer and return to Venice, while his wife Yolanda of Flanders sailed on to Constantinople. Like the Norman invasion of William II of Sicily (r. 1166-89) in 1185, after capturing Dyrrhachium, Peter intended to follow the ancient Via Egnatia to Thessalonica, wresting Albania and Macedonia from Epirote control in the process. The commonly accepted version of events is that Dyrrhachium resisted with success, and as his casualties mounted Peter was forced to raise the siege and start his march towards Thessalonica. The march proved difficult, due to both the harsh terrain as well as the open hostility of the local population. After a few days, Theodore with his army confronted Peter. Theodore requested talks with the papal legate, de, whom he assured of his goodwill and support. Western sources claim that he offered to recognize the primacy of the Catholic Church and the suzerainty of the Latin Empire—as well as to support Peter in his planned participation in the Fifth Crusade—and offered the Latins food and guides through the mountains. Peter was glad to receive this unexpected help, and an agreement between the two was concluded. As soon as the Latins let their guard down, however, Theodore fell upon them. Peter of Courtenay, Colonna, the Latin Archbishop of Salona, Count fr, and many Latin nobles were taken captive, while Peter's army scattered into small roving bands trying to survive. Some sources on the other hand—Akropolites, the chronicler Ephraim, and three Western chronicles—claim that Dyrrhachium was captured, and are followed by some modern scholars, including the Greek I. D. Romanos and the French Alain Ducellier. According to this view, Theodore offered to acknowledge Peter's suzerainty after the city's fall, only to treacherously ambush and defeat him. As the historian John V. A. Fine remarks, however, "it is not important which version is correct"; the outcome was the same, and if lost, Dyrrhachium was quickly retaken after Peter's capture. Historian Philip Van Tricht on the other hand offers a completely different interpretation of events to the traditional view. He considers that until the ambush and capture of Peter of Courtenay, Theodore, like his brother before him, had still recognized the suzerainty of the Latin Empire while remaining de facto autonomous, and that it was Peter's attempt to return Dyrrhachium to Venice, as well as the increased papal interference in Greek affairs, that prompted him to break his vassalage and pursue a course of open confrontation with the Latins.

Whatever the true course of events, Theodore's unexpected victory echoed throughout the Greek world, and greatly enhanced his standing; even the usually hostile Akropolites was forced to admit in his history that this feat was "of great help to the Romans". Conversely it dismayed Pope Honorius, who sent letters to the Latin princes of Greece as well as the Doge of Venice and Peter of Courtenay's son-in-law King Andrew II of Hungary (r. 1205–35), urging them to engage themselves to secure the release of Peter and Colonna. He even wrote to Andrew and the French bishops to call for a crusade against Theodore, with which he also threatened Theodore in a letter. With the first contingents for the crusade began assembling at Ancona in late 1217, and the Venetians eager to profit from the crusade to recover Dyrrhachium, the pressure bore fruit: in March 1218, Colonna was released, with Theodore offering his apologies and assurances of loyalty to the Pope. Honorius then changed his policy to the point of forbidding the Doge of Venice to harm Theodore in the slightest, hoping thereby to secure the release of more prisoners. Although some of the lesser barons were freed, however, neither Peter nor many of the most senior lords remained in captivity until their death. It is unknown when Peter of Courtenay died, but this was probably before September 1219. The capture of Peter of Courtenay left both major Latin states in Greece, Thessalonica and Constantinople, in the hands of female regents. Before arriving in Constantinople, where she gave birth to Peter's posthumous son, Baldwin II (r. 1228–73), Yolanda had stopped at the Peloponnese. There she quickly appreciated the wealth and strength of the Principality of Achaea, and arranged the marriage of her daughter Agnes to the principality's heir, Geoffrey II of Villehardouin (r. ca. 1229–46). A politically astute ruler, Yolanda also secured her eastern border by offering her daughter Maria of Courtenay in marriage to Theodore Laskaris, who had just been widowed for the second time.

Before launching his final stroke against Thessalonica, Theodore also took care to secure his southern flank, by appointing his brother Constantine Komnenos Doukas as governor in Aetolia and Acarnania. An energetic governor, Constantine not only effectively shielded the Epirote domains from the threat of the Duchy of Athens, but soon recovered Neopatras and Lamia as well. Theodore himself turned his attention to clearing Thessaly of any remaining Latin presence, culminating in the surrender of the great Platamon Castle in 1218. Over the next few years, one by one, Theodore captured the fortresses around Thessalonica itself. Platamon controlled the entrance to the Thermaic Gulf, and with the surrender of Serres in late 1221, Theodore cut the land connection between Constantinople and Thessalonica as well. Thessalonica was left thereby, in the words of John Fine, "more or less an island in the midst of Theodore's possessions".

As the fall of Thessalonica appeared imminent, Pope Honorius excommunicated Theodore, ordered an embargo on horses, troops, and supplies from the Adriatic ports, and sent letters to Constantinople urging assistance to Demetrius. Demetrius himself went to Italy to seek aid, being received by the Pope in Rome in March 1222 and by Emperor Frederick II (r. 1220–50) soon after. A crusade was proclaimed against Theodore, and troops began to gather in Italy. In the meantime, the Latin Empire, now under Robert of Courtenay (r. 1221–28), was once more embroiled in warfare with Nicaea as it supported Laskaris' brothers in their challenge against the new Nicaean emperor, John III Doukas Vatatzes (r. 1222–54). The first detachments of the assembling crusade, under Count Oberto II of Biandrate, arrived at Thessalonica in summer 1222 and joined the de facto regent, Guy Pallavicini. Theodore now hastened his move against Thessalonica. After preliminary operations in late 1222, in early 1223 he laid siege to the city. Honorius excommunicated him again, and redoubled his effort to promote the crusade, which had come to a standstill in the meantime. At the Pope's urging, Venice and Emperor Frederick promised aid. Robert of Courtenay also pledged to assist, while Honorius called upon the Latin princes of southern Greece to join in the effort. The crusade finally assembled at Brindisi in March 1224. In his instructions to his legate, however, Honorius did not rule out the possibility of Theodore coming to terms with the Crusaders. True to his word, in April 1224 Robert of Courtenay sent an army to besiege Serres. During the siege, however, the Latin generals learned of the disastrous defeat of the main Latin army at the hands of John III Doukas Vatatzes at the Battle of Poimanenon. They lifted the siege and hastened back to Constantinople, only to be intercepted by Theodore's men; most of the Latin army were killed or taken prisoner. This double disaster destroyed the Pope's plans for the crusade, as he had envisaged it to land in Theodore's rear while he was engaged with Robert's army. At the same time, the prospective leader of the crusade, Demetrius' half-brother William VI of Montferrat, fell ill. In November, the Pope was forced to postpone the crusade's departure for the next spring. With news of the Latin defeats and the postponement of the crusade, the exhausted defenders of Thessalonica surrendered the city to Theodore sometime in December 1224. The crusade to relieve it sailed in March 1225, and landed in Thessaly at Halmyros. The Crusader army however was soon decimated by dysentery, allegedly because the Greeks had poisoned the local water supply. William of Montferrat himself succumbed to it, and the remnants of the army left Greece. Demetrius of Montferrat still hoped to recover his realm with the help of Frederick II, but died in 1227.

Emperor of Thessalonica
The capture of Thessalonica, traditionally the second city of the Byzantine Empire after Constantinople, was a major stroke against the Latins and greatly boosted Theodore's standing, so much that he now regarded himself as superior to Vatatzes, and openly claimed the Byzantine imperial title by putting on the purple boots reserved to the emperor. Indeed one of his major supporters, the eminent Metropolitan of Naupaktos, John Apokaukos, in a letter to the Patriarch in 1222 openly declared that the Epirotes already regarded Theodore as their "God-sent regent and emperor", and later wrote to Theodore's wife expressing the hope to be able to assist at their imperial coronation at Thessalonica. According to Byzantine custom, the coronation of an emperor could only take place in Constantinople and be performed by the Patriarch, but Constantinople was still in Latin hands an the Patriarch (now Germanus II, 1223–40) resided in Nicaea; Theodore thus turned to the Metropolitan of Thessalonica, Constantine Mesopotamites, whom he had just restored to his see after removing the Latin prelate. Mesopotamites however recognized the Patriarch at Nicaea as legitimate and steadfastly refused to perform the rite, despite pressure from Theodore, his brother Constantine, and John Apokaukos. Rather than submit, he preferred to return to exile. In response, in March 1225 Theodore convened a council of bishops of his domains at Arta, chaired by Apokaukos. The council approved a declaration, composed by Apokaukos, which extolled Theodore's achievements against Latins and Bulgarians, his liberation of Greek lands, eviction of Catholic priests and restoration of Orthodox bishops, and his imperial descent, and declared that the council recognized only him as emperor. Armed with this declaration, Theodore had the loyal Archbishop of Ohrid, Demetrios Chomatianos, perform the coronation instead.

Although Theodore appears to have assumed and was addressed by the imperial title almost immediately after the capture of Thessalonica, the date of his actual coronation is unknown. The French scholar Lucien Stiernon placed it in the period between June 1227 and April 1228, but the Greek Apostolos D. Karpozilos rejected this, reasoning that Theodore had no obvious reason to delay his coronation for so long, and suggested that he was crowned in 1225, immediately after the council of Arta. Eleni Bees-Seferli on the other hand, based on the letters of Apokaukos, suggested a date between 3 April and August 1227, while Alkmini Stavridou-Zafraka narrowed the date down to 29 May 1227.

As befitted an emperor, Theodore began setting up a court at his new capital, and dispensed court titles to his relatives and followers. His brothers Manuel and Constantine were raised to the rank of Despot, the long-serving John Plytos became panhypersebastos and mesazon (chief minister), while a number of scions of old Byzantine aristocratic families, who had sought refuge in Epirus, were appointed as provincial governors—the title of doux was used, but unlike earlier times these were mostly civilian governors with little military authority–alongside members of the local aristocracy. Theodore awarded titles with such largesse that formerly exclusive titles such as pansebastos sebastos or megalodoxotatos were devalued and came to be held by city notables. To secure his new capital, Theodore instituted a guard of "Tzakones" under a kastrophylax.

John Vatatzes initially reacted to Theodore's proclamation as emperor by offering to recognize him as a sort of viceroy in his lands, but Theodore rejected this and publicly assumed the full titelature of the Byzantine emperors, as "basileus and autokrator of the Romans". Theodore's coronation deepened the rift between the western Greeks and Nicaea, which once again was expressed in the ecclesiastic sphere. At first, the Nicaeans tried to limit the blame on Chomatianos: while writing respectfully of Theodore himself, Patriarch Germanus II expressed his indignation at the presumption of Chomatianos to usurp the patriarchal privilege of crowning an emperor, while Chomatianos claimed that, as the successor of the ancient see of Justiniana Prima, he was an independent prelate and had the authority to do so. In 1227, a synod of Epirote bishops in Arta tried to find a compromise, acknowledging the overall authority of the Patriarch at Nicaea but requesting administrative autonomy, i.e. for Theodore the right to appoint bishops in his domains. They gave the Patriarch three months to reply, and suggested that if he did not heed their proposals, they might be forced to recognize the supremacy of the Pope instead. Germanus replied by having the patriarchal synod condemn Theodore's assumption of the imperial title. The conflict escalated when Germanus appointed his own candidate to the vacant see of Dyrrhachium. Theodore expelled the bishop, and the Epirote synod instead elected a friend of Chomatianos, Constantine Kabasilas, as the bishop. Germanus now attacked Theodore directly. In response, George Bardanes composed a letter to Germanus, which insisted on Epirote ecclesiastical autonomy and challenged the very legality of Germanus' claims to the patriarchate. The result was a full schism between the Nicaean and Epirote churches, that lasted until 1232/3.

Following Theodore's coronation, there were four rulers who claimed the imperial title and Constantinople: the Latin Emperor, Robert of Courtenay, Theodore, John III Doukas Vatatzes of Nicaea, and the young but ambitious John II Asen (r. 1218–41) of Bulgaria. The Latin Empire was a shadow of its former strength: following Poimanenon, the Latins had lost most of their territories in Asia, while in Europe, it was soon reduced to the environs of Constantinople itself. Already in 1224, or at least in 1225, Theodore captured Chalcidice with Mount Athos, and in spring 1225, he advanced through the eastern Macedonia and western Thrace, seizing Christopolis, Xanthi, Gratianopolis, Mosynopolis and Didymoteicho. Trying to pre-empt him and block his advance onto Constantinople, the Nicaeans had answered the summons of the inhabitants of Adrianople and taken over the city from the Latins. Theodore however crossed the Evros River and blockaded the city, until it agreed to surrender. The Nicaean army, under the protostrator Ises and John Kamytzes Komnenos, was allowed to withdraw unmolested to Asia with ships provided by Theodore.

The capture of Adrianople opened the path to Constantinople for Theodore. In order to secure his northern flank, he concluded an alliance with John Asen, sealed by the (second) marriage of his brother Manuel to Maria, an illegitimate daughter of Asen. At the same time, the Latins turned to Nicaea and concluded a peace treaty in exchange for further territorial concessions. This pact too was sealed by a marriage, of Theodore Laskaris' daughter Eudokia to the Latin baron Anseau de Cachieu. In the same summer of 1225, Theodore led his army to the environs of Constantinople, reaching the towns of Bizye and Vrysis. Anseau of Cachieu, leading the Latin army, was heavily wounded in the clashes, but Constantinople itself was not attacked. Not only was Theodore unprepared for a siege against the mighty Theodosian Walls, but news of William of Montferrat's landing at Thessaly forced him to break off operations and return west.

Nevertheless, for reasons that are unknown, Theodore did not renew his attack on Constantinople in 1226 or the years thereafter. Instead, he seems to have occupied himself with domestic affairs, as well as taking care to improve relations with Frederick II during the latter's stop-over at Corfu and Cephallonia to lead the Sixth Crusade in 1228. In 1229, he even sent a company of Greek troops to serve under Frederick in Italy. At the same time, Theodore presided over a rupture in relations with Venice, after his governor in Corfu sequestered the cargo of a shipwrecked Venetian ship. Theodore issued an edict on 19 August 1228 prohibiting Venetian merchants from practising commerce in his realm. In January of the same year, Robert of Courtenay died, leaving the throne of the Latin Empire to his eleven-year-old brother, Baldwin II (r. 1228–73). With a regency taking over the governance of the state, the Latin Empire stood further enfeebled. At this moment, John Asen offered an alliance. Baldwin II would marry his daughter Helena, while John Asen would take over the regency and lend his assistance at repelling Theodore's attacks. The Latin barons viewed the offer with mistrust, as it would offer John Asen every opportunity to take over Constantinople himself; instead, they strung out negotiations, and eventually chose the 80-year-old but energetic John of Brienne (r. 1229–37) as regent. Although the Bulgarian offer failed, it served to open a rift between Theodore and his nominal ally. In a move clearly directed against John Asen, in September 1228, Theodore agreed to a one-year truce with the Latin Empire's regent, Narjot of Toucy, with the border between the two empires running along a line from Ainos and Vrysis.

Klokotnitsa and Bulgarian captivity
Finally, in late 1229, Theodore began assembling his forces at Thessalonica—including a contingent of troops sent by Frederick II—for the projected final attack on Constantinople. As his troops marched east in spring 1230, however, he unexpectedly turned his army north and followed the Evros valley into Bulgaria. Theodore's motives for this sudden change are debated. Contemporary and later historians like Akropolites denounced this as a sign of Theodore's duplicity and treachery, but a more likely suggestion is that Theodore, hitherto undefeated in battle, desired to check Bulgarian power and avoid the possibility of the Bulgarians striking in his rear while he was engaged in besieging Constantinople. Although caught by surprise, John Asen reacted rapidly. Allegedly affixing the text of the broken treaty to one of his spears as a flag, he rallied his troops and met Theodore in battle in April 1230. The ensuing Battle of Klokotnitsa was a crushing victory for the Bulgarian ruler, who took Theodore and many of his officers captive.

In the aftermath of Klokotnitsa, Bulgaria emerged as the mightiest power in the Balkans. Deprived of its energetic ruler, Theodore's empire collapsed: within a few months Thrace, most of Macedonia, and Albania, fell under Bulgarian rule. As John Asen boasted in an inscription in the Holy Forty Martyrs Church at his capital of Tarnovo, he "occupied all the land from Adrianople to Dyrrhachium, Greek, Serbian, and Albanian alike", although Dyrrhachium itself apparently remained in Greek hands. The Latin Duchy of Philippopolis was also annexed, and Alexius Slav's principality in the Rhodope Mountains was extinguished in the process, with Alexius spending the rest of his live at Asen's court.

The throne in Thessalonica was now occupied by Theodore's brother Manuel, who managed to escape from Klokotnitsa. His domain was reduced to the environs of the city, and his family's core territories in Epirus and Thessaly, as well as Dyrrhachium and Corfu, while his brother Constantine in Aetolia and Acarnania recognized his suzerainty. As a son-in-law of John Asen, Manual was allowed to maintain internal autonomy, but to all intents and purposes he was a client of the Bulgarian tsar. Manuel soon lost Epirus to Michael I's bastard son Michael II. Returning from exile, Michael quickly succeeded, apparently with the support of the local population, in taking over control of Epirus. Manuel was forced to recognize the fait accompli under the pretence that Michael recognized his suzerainty, in token of which Manuel conferred him the title of Despot. In reality Michael was fully independent, and very quickly ceased to acknowledge Manuel's suzerainty; by 1236, he had seized Corfu. In order to preserve some freedom of manoeuvre and counter Asen's attempts to subordinate the Epirote Church to the Bulgarian Church of Tarnovo, Manuel turned to his brother's erstwhile rivals in Nicaea and brought an end to the ecclesiastical schism by acknowledging the legitimacy and superiority of the Nicaea-based Patriarch.

Theodore himself remained in captivity at Tarnovo for seven years. Initially he was treated with honour, but at some point during his captivity he was accused of plotting against John Asen and blinded as a result. This was the customary Byzantine punishment for treason and means of sidelining potential political rivals. According to a recently discovered letter, Asen initially ordered two Jews to carry out the deed, for Theodore had been persecuting the Jews in his territory and confiscating their wealth to fund his campaigns. Theodore however begged to be spared, and they refused to carry out the blinding, whereupon the enraged Tsar had them thrown from a cliff. Finally, in 1237 Theodore was released when Asen, recently widowed, fell in love with Theodore's sole unmarried daughter, Irene. Immediately after the marriage, Theodore was released and allowed to depart Tarnovo to wherever he wished.

Recovery of Thessalonica and death
As soon as he was set free, Theodore returned to Thessalonica. Lacking any escort or followers, he disguised himself as a beggar in order to enter the city in secret. There he contacted old supporters and favourites, and organized a conspiracy that soon took ousted Manuel and over the city. As Byzantine custom barred him from re-assuming the imperial office due to his blinding, Theodore installed his son John Komnenos Doukas as emperor (without a coronation ceremony), but remained the real ruler of the empire in his son's name. John himself appears to have been mostly interested in religion, and rather inclined to enter a monastery than being emperor. Theodore had to persuade him that being named emperor was a God-given gift, and that he was indeed the rightful Emperor of the Romans due to his imperial descent.

The deposed Manuel was sent to exile at Attaleia in Asia Minor, while his wife Maria was allowed to return to her father. Despite Theodore's actions and the overthrow of his daughter and son-in-law, Akropolites reports that John Asen remained favourably disposed towards Theodore due to his passionate love for Irene. Manuel did not remain quiescent in exile, however. Determined to avenge himself, from Attaleia he secured passage through Turkish lands to Nicaea. There John Vatatzes welcomed him and agreed to support him, but not before he secured from Manuel oaths of loyalty to himself. Thus in in early 1239 Manuel with six Nicaean ships set sail for Greece, landing at Thessaly near Demetrias. He received widespread support in the province, perhaps even from the local governor, Michael I's son-in-law Constantine Maliasenos, allowing him to raise an army and in a short time occupy Farsala, Larissa, and Platamon. Before the spectre of civil war, Manuel and Theodore eventually came to terms by dividing the state of Thessalonica among themselves: renouncing his allegiance to Vatatzes, Manuel received Thessaly, John and Theodore kept Thessalonica and the remaining parts of Macedonia as far west as Vodena and Ostrovo, and Constantine was confirmed in his appanage of Aetolia and Acarnania. To further secure their position, both Theodore and Michael concluded treaties with the powerful Prince of Achaea, Geoffrey II of Villehardouin.

Michael II in Epirus was not part of the brothers' agreement, and continued to pursue his own policies independently of his uncles. In 1241, when Manuel died, Michael moved quickly to occupy Thessaly. In June of the same year, John Asen died, leaving the throne to his seven-year-old son Kaliman (r. 1241–46). Coupled with the increasingly deteriorating situation of the Latin Empire, this development left John Vatatzes of Nicaea as the pre-eminent ruler of the region, and the obvious candidate for the capture of Constantinople. Before undertaking any moves against Constantinople, however, Vatatzes realized the need to settle affairs with Thessalonica, and in particular with Theodore, whose ambition, capability, and machinations he feared. In 1240 or 1241 he therefore issued an invitation, with assurances of safe-conduct, to Theodore to visit Nicaea. Theodore accepted, and was treated with great honours by Vatatzes, who deferred to him as his "uncle" and dined with him at the same table. In reality, however, Theodore was a prisoner in Nicaea; he was not allowed to leave, and throughout his sojourn in the Nicaean court, preparations were in full swing for a campaign against Thessalonica. In spring 1242, Vatatzes crossed over into Europe at the head of his army, with Theodore accompanying him as an honorary prisoner. Facing no resistance, the Nicaean army and fleet arrived before Thessalonica. The city's garrison and inhabitants resisted with valour and the Nicaean army, lacking heavy siege equipment, had to settle for a drawn-out blockade. Soon, however, news arrived of a Mongol invasion of Asia Minor, which forced Vatatzes to break off the campaign and return to Nicaea. Nevertheless, the Nicaean emperor kept these news a secret, and sent Theodore to his son to negotiate. John himself reportedly was willing to surrender the city outright, but his father convinced him to hold out for better terms. In the end, after 40 days of negotiations, John was allowed to keep control of Thessalonica, but renounced his imperial title and accepted Nicaean suzerainty and the title of Despot. Theodore was also allowed to remain at Thessalonica at his son's side.

John ruled as Despot in Thessalonica for two years, until his death in 1244. Theodore himself retired to Vodena, from where he supervised the affairs of state. On John's death he raised his younger son Demetrios Komnenos Doukas in his place, and sent an embassy to Nicaea to announce the succession, as befitted the terms of vassalage agreed in 1242. If John was a religious ascetic, Demetrios was a dissolute youngster who enjoyed partying with his favourites and seducing married women. Although Theodore remained in charge of governance, Demetrios quickly became so unpopular that many leading citizens began viewing direct Nicaean rule with favour. Things came to a head in autumn 1246, when Kaliman of Bulgaria died, leaving the country in the hands of a regency for his younger brother Michael Asen (r. 1246–57). Vatatzes quickly attacked Bulgaria, and within three months captured most of Thrace and all of eastern and northern Macedonia, while Michael II of Epirus also took advantage of the opportunity to expand into Albania and northwestern Macedonia. At the close of this campaign in November, as Vatatzes was encamped at Melnik, he was informed of a conspiracy to depose Demetrios and deliver Thessalonica in exchange for a chrysobull guaranteeing the traditional rights and privileges of the city. Vatatzes readily granted this, and sent envoys to Demetrios calling for him to appear in person at his camp. Demetrios, suspicious of Vatatzes' intentions, refused, and the Nicaeans marched on Thessalonica. After a few days, the conspirators opened one of the gates to the Nicaean army, and the city was quickly captured. Demetrios was captured and exiled to Lentiana in Bithynia, while Thessalonica and all of Macedonia were placed under the governance of the Grand Domestic Andronikos Palaiologos. Theodore himself, isolated and without power in his refuge at Vodena, apparently remained uninvolved in these events.

With Thessalonica secured, Vatatzes turned to Epirus, offering Michael II a marriage alliance between Michael's eldest son Nikephoros and his own granddaughter Maria. The offer was enthusiastically accepted by Michael's wife, Theodora Petraliphaina, and the young couple was engaged at Pegae. Michael, who had not abandoned his family's ambitions, remained ambivalent about the Nicaean alliance, and Theodore used his influence over his nephew to turn him against it. Thus in spring 1251, Michael launched a sudden attack on Thessalonica. The city resisted successfully, and in spring of the next year Vatatzes once more crossed into Europe to campaign against the Komnenoi Doukai. Theodore with Michael had turned to the north, capturing Prilep and Veles, and when they received news of Vatatzes' arrival, they withdrew to Epirus via Kastoria. Vatatzes besieged and captured Theodore's stronghold of Vodena, but soon became bogged down in skirmishing in the area of Kastoria. The stalemate was broken when two Epirote generals, John Glabas and Theodore Petraliphas, defected to the Nicaeans, followed shortly after by the ruler of Kruja, Golem. This forced Michael to come to terms with Vatatzes, ceding the fortresses he had captured as well as his remaining holdings in Macedonia, and reconfirming the marriage alliance with Nicaea. Furthermore, Vatatzes explicitly demanded the handing over of Theodore. The Epirote ambassadors met Vatatzes at Vodena, where they handed over Theodore and the young Nikephoros as a hostage. While the latter was granted the title of Despot and soon allowed to return to Epirus, Theodore was moved as a prisoner to Asia Minor. There he died shortly after, in ca. 1253.

Assessment
The biographer of the Komnenoi, Konstantinos Varzos, described Theodore as an "energetic, resourceful, and exceedingly ambitious statesman, who inherited from his ancestor Alexios I Komnenos his endurance and persistence, but not the latter's intelligence, diplomacy, and ability to adapt". He furthermore points out that despite his great ability, his ambition to be the one to recover Constantinople and irreconcilable rivalry with Nicaea actually hampered and delayed the restoration of the Byzantine Empire by several decades.

The Byzantinist Donald Nicol also remarks that "the memory of Theodore Doukas's victories and of his title to the Byzantine crown lived on in northern Greece and in the hearts of his descendants for many years to come". Indeed, Michael II continued his uncle's rivalry with Nicaea, further delaying the recovery of Constantinople, and even after the restoration of the Byzantine Empire by Nicaea in 1261, the rulers of Epirus would continue to challenge the revived empire "for what they believed to be their own right to the throne".

Family
By his wife Maria Petraliphaina he had four children:
 * 1) Anna Angelina Komnene Doukaina who married King Stefan Radoslav of Serbia
 * 2) John Komnenos Doukas, who became Emperor of Thessalonica in 1237
 * 3) Irene Komnene Doukaina, who married John Asen
 * 4) Demetrios Komnenos Doukas, who succeeded as ruler of Thessalonica in 1244