Long campaign

Crusade of Varna
King Władysław III of Poland in the Battle of Varna, by Jan Matejko
Date October 1443-November 1444 Location Balkans Result Decisive Ottoman victory
Belligerents
Kingdom of Poland Kingdom of Hungary Crown of Bohemia Grand Duchy of Lithuania Wallachia Principality of Moldavia Bulgarian rebels  Holy Roman Empire Papal States Teutonic Knights	Ottoman Empire
Commanders and leaders
Władysław III of Poland † John Hunyadi Mircea II Fruzhin	Murad II

The Crusade of Varna was a string of events in 1443–44 between the crusaders and the Ottoman Empire. It culminated in a decisive Ottoman victory at the Battle of Varna on 10 November 1444.

In 1428, while the Ottoman Empire was fighting a war with the Republic of Venice, the Ottomans and the Kingdom of Hungary achieved a temporary peace by establishing the Serbian Despotate as a buffer state. After the war ended in 1430, the Ottomans returned to their earlier policy of controlling all lands south of the Danube. In 1432, Sultan Murad II began raiding into Transylvania. After King Sigismund died in 1437, the attacks intensified, with the Ottomans occupying Borač () in 1438 and Zvornik and Srebrenica in 1439. At the end of 1439, Smederevo capitulated and Murad succeeded in making Serbia an Ottoman province. Đurađ Branković, Despot of Serbia, fled to his estates in Hungary. In 1440, Murad besieged Hungary's main border fortress, Belgrade. After failing to take the fortress, he was forced to return to Anatolia to stop attacks by the Karamanids.

Meanwhile, Sigismund's successor Albert had died in October 1439, shortly after signing a law to "restore the ancient laws and customs of the realm". The law restricted the royal authority by requiring the participation of landed nobility in political decisions. Four months after Albert's death, his only son, Ladislaus, was born while Hungary was in the midst of a civil war over the next monarch. On 17 July 1440 Vladislaus, king of Poland, was crowned despite continuing disputes.John Hunyadi aided Vladislaus's cause by pacifying the eastern counties, gaining him the position of Nádor of Transylvania and the corresponding responsibility of protecting Hungary's southern border. By the end of 1442, Vladislaus had secured his status in Hungary, and denied an Ottoman proposal of peace in exchange for Belgrade.

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Wikipedia