After a failed expedition in 1441/1442 against Belgrade, the Ottoman sultan Murad II signed a ten-year truce with Hungary. After he had made peace with his foe Karaman in the east in August 1444, he resigned the throne to his 12-year-old son Mehmed II.
Despite the peace treaty, Hungary co-operated with Venice and the pope to organize a new crusader army. On this news Murad was recalled to the throne.
A mixed Christian army consisting mainly of Hungarian and of Polish forces, but with detachments of Czechs, papal knights, Bosnians, Croatians, Bulgarians, Romanians and Routeni (Old Russians), met with a numerically superior force of Ottoman Turks. The Hungarians were ill-equipped, and promised support from Wallachia, Bulgaria, Albania and Constantinople did not arrive. The 30,000 Crusaders were overwhelmed by 120,000 Turks. Over half of the soldiers from the united army perished.
The defeat ended any serious attempts to prevent the conquest of eastern Europe by Turks for several decades and the death of Wladyslaw III in the battle left Hungary in the hands of the four-year-old Ladislaus Posthumus of Bohemia and Hungary.
See History -- Military history -- List of battles -- History of Poland -- History of Hungary