Siege of Jajce

The Siege of Jajce was a siege in 1463 and was part of the Ottoman–Hungarian Wars. The Hungarian victory meant the maintenance of Christiandom in Bosnia and – with the repulse of Ottoman forces – the protection of Hungarian territories for the 15th century.

Background
Beginning from the diet of Buda of 1462 some Bosnian-Hungarian borderline fortresses were already guarded by the Kingdom of Hungary and King Stephen Tomašević of Bosnia was accepted as a vassal to her. The Bosnian King refused to pay tribute to the Porte thereafter. As a consequence both Ottoman and Christian sides began the war preparations. Sultan Mehmed II gathered an army of 150,000 soldiers in Adrianopolis and departed for the Lower Danube area in April 1463. As a part of a diversion attack he commanded Ali Bey Mihaloğlu to invade southern parts of the Kingdom of Hungary. The bey crossed to Syrmia, but was pushed back by Andrew Pongrácz high cup-bearer of Hungary. He suddenly made a flanking move to the heart of Hungary until he reached Temesvár, where he ran into John Pongrácz Voivode of Transylvania and was defeated in a fierce battle. Meanwhile Mehmet II advanced to Travnik, which he besieged. Then moved to the capital city Bobovac that fell within three days. Stephen Tomašević was advised to entrench himself in the high mountains although he chose to withdraw to Jajce and later to Ključ and burnt the bridges of the roads along. Turahanoğlu Ömer Bey pursued his trail taking Jajce without a fight and pushed to Ključ through the Sava river and the surrounding mountains despite the marshy ground and the general inaccessibility to the town. Seeing himself in a dead-end situation Tomašević set his wife and mother to a journey through Raguse to Hungary to find refuge. He fortified himself in Ključ fortress. After their arrival the Ottomans set fire around the city thus forcing the inhabitants to surrender in despair. Mahmud Pasha Angelović granted the Bosnian King. He swore an oath to the sultan and capitulated when he was promised safe retreat in return. He had to spread this agreement to the remaining fort captains in 8 days and as a result 70 places and one million florins were handed to the Porte. Discontent with this agreement Mehmet rebuke Mahmud and instructed him to transport the Bosnian King to his court. Stephen Tomašević was double crossed and despite his oath to the Sultan the last ruler of Bosnia was beheaded at Carevo Polje near Jajce.

The sultan divided his expeditionary army into three, one led by him, one by Ömer Bey and one by Mahmud Pasha, respectively, and raided the surrounding countries as well as completed the conquest of Bosnia. Ömer Bey surged in the direction of the Kingdom of Croatia, while Mehmet moved towards the Duchy of Saint Sava. In Croatia Ömer Bey confronted and slew Paulus de Speranchich Ban of Croatia and his entourage of 800 men. With the help of the Bogumils, Stjepan Vukčić Kosača was able to withstand the intrusion of Mehmet for a short time, before sending his youngest son as a hostage to Istanbul, and ceding all of his lands to the north of Blagaj Fort to the Empire.

Premise
Mehmet II chose not to engage in winter operations and retreated bringing 100,000 prisoners and leaving Mimert (Minnet) Bey in charge in Bosnia. He also didn't have other choice as their horses were exhausted and the supply lines were inefficient. King Matthias Corvinus sent a couple thousand ecclesiastic army to the Lower Sava Valley and the Black Army of Hungary led by John Pongrácz de Dengeleg and supplemented by the Szeklers to the village of Keve. He also envoyed a garrison to his Adriatic subject, the Republic of Ragusa as a preventive measure. He also commissioned ambassadors to the Signoria of Venice and Pope Pius II. Both of them promised financial aid, the Holy See granted a sum sufficient for the military service payment of 1000 cavalry for an year. Venice offered 20,000 ducats for the Anti-Ottoman defense. Matthias ordered all dispensable transport points to sail to the enlist point at Petrovaradin. Matthias sought a long-term alliance with Venice. In 12 September just before the launch of the attack Matthias and Venetian orator John Emo in the camp in Petrovaradin. The terms were:
 * They form a mutual protective and offensive alliance against the Turks
 * They don't conclude peace unbeknownst to the other
 * The Republic of Venice provides 40 galleys and puts all of her Dalmatian and Peloponnese captains on a war footing
 * The parties involved won't violate each other's territorial integrity

The Duchy of Saint Sava hesitated between the Ottomans, Venice and Hungary to be subjugated to. In October they came to the decision to offer themselves to Venice. Already an ally to Hungary the Doge of Venice Cristoforo Moro gently replied that Hungary had already made the necessary steps to relieve Bosnia, her armies entered Bosnia and besieged Jajce as well as the other fortresses. Following the events Stjepan Vukčić Kosača lended himself to Matthias who accepted his service. In exchange Vladislav Hercegović was promoted a Hungarian banner lord and reassured the estates of Stjepan. This ancillary alliance was signed on 6 December.

Siege
Matthias branched off his army into two divisions. The first led by Emerich Zápolya was about to approach Jajce from the North along the Vrbas river, while the other led by the King himself carried the siege weapons and chose the network of paved roads (kaldrma) from the North-West to Ključ liberating each city connected. The population welcomed the troops and even joined them as the Franciscan clergy maintained a religious unrest throughout Bosnia. He appointed John Pongrácz de Dengeleg as the supplies overseer and Provost Gaspar Bak of Berend as the ammunition/siege engines operator. The third contingent was recruited in Croatia thus it arrived from West from the direction of Bihać and commanded by Martin Frangepan, while the Saint-Savan reinforcements blocked Jajce the from the South (Prozor, Donji Vakuf) in November Matthias reached the town in a 4–5 four days march, which is considered quite a fast progress regarding the mediaval infrastructure conditions. Upon the recent success among the Bosnian population Matthias anticipated local support and so he instantly attacked the town of Jajca in 5–6 October that was subdued for the first try. After a short hand-to-hand combat the Ottoman garrison locked itself in the Jajce Fortress.

The siege possibly started at the confluence of Pliva-Vrbas and the siege machines were installed in the half-circle of Carevo Polje-Borci-Baščeluci. Though the contemporary cannons could cause little damage to the walls as their fire range varied from 300 to 900 meters, which was also the range covered by the archery of the defenders. The King exhorted his troops by giving out letters of land donation to those who emerged in battle. In order to officially induct these manors he set up his own chancellery in the camp to administrate them. On the day of the planned general offensive the captains of the fortress called for surrender talks, which led to an agreement the same day. Those who wanted to leave could do so without their slaves the rest was free to join the Black Army. Around 400 soldiers chose to be drafted into the Hungarian army including the head captain Yusuf Bey.

Aftermath
The smaller forts in the region were quickly recovered and were reorganized as a part of the Hungarian Banate of Jajce. Matthias Corvinus appointed John Székely of Hídvég as the new captain and Emerich Zápolya as the new governor of Bosnia. Vladislav Hercegović was awarded the Župas of Gornji Vakuf-Uskoplje and Prozor-Rama.

King Matthias Corvinus also gifted the fortress of Medvedgrad to the Frangepans for their merits in the siege. Stephen Gerendi saved his life when he shot a waylaying Turk during the siege and thus was rewarded the right to bear personal coat of arms.

The Venetian-Ottoman conflict escalated into the Ottoman–Venetian War.