The siege of Jajce was a siege of the town of Jajce and its citadel in 1463, in a push by Ottomans to conquer as much of the Bosnian Kingdom, and continuation of the Ottoman–Hungarian Wars. After the fall of Travnik and royal fortress of Bobovac, in the initial days of invasion, Ottomans, led by Sultan captured the town. One of the parties pursued Bosnian King Stjepan Tomašević, and caught up with him at Ključ fortress, after which he was brought to Jajce and executed. Soon the Ottomans forces withdraw, leaving the town under the protection of a small garrison. The Hungarian took the opportunity to capture the citadel, and this meant that Ottoman advancement in Bosnia was halted for the time being. The northern part of Bosnia were brought under Hungarian control, and divided into three administrative regions, Banate of Jajce, Banate of Srebrenik, established around Srebrenik fortress, and a puppet statelet named "Bosnian Kingdom". This situation and Jajce under Hungarian garrison will last until 1527 when the Ottomans finally took the town, and breaking the lines advanced northward to Hungary and westward to Bihać, which was part of the Kingdom of Croatia.
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 preparing for war.
Sultan Mehmed II gathered an army of 150,000 soldiers in Adrianopolis and departed for the Lower Danube area in April 1463. As part of a diversionary 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. He 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 rebuked 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 Hum. In Croatia Ömer Bey confronted and slew Paulus de Speranchich, Ban of Croatia, and his entourage of 800 men. With the help of the Krstjani, 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.