Siege of Ostrvica

After the death of Sultan Murad II and the conquest of Istanbul, the Serbian despot sent a delegation to the Ottoman ruler who was in Edirne. He presented the keys of some castles that belonged to the Ottomans, as well as congratulating the conquest. But at the same time, with the encouragement of the Pope, he had not neglected to meet with the Hungarians to participate in a new Crusade, which was intended to be prepared against the Ottomans. The Ottomans learned about the Serbian-Hungarian contacts of the Serbian despot against them through their spies and prepared accordingly.[3]

Although the Ottoman court asked the Serbian delegation for the keys of the other castles, which belonged to them but passed to the Serbs, they also received the refusal. Thereupon, a campaign was made on Serbia in the spring of 1454.[4]

Mehmet led this expedition in 1454. His intention this time was simply to cross enemy territory and destroy everything. During this fast expedition, thousands of prisoners were taken and brought to Istanbul as the new Christian population. Trapped in Smederevo, the cavalry sent against him by the despot (a Venetian visiting John Hunyadi says he had 9,000 horsemen) was easily repulsed. Mehmed the Conqueror arrived in Ostrvica, where Branković had many assets, and easily took the castle.[5]