The princes of Europe were slow in responding to the call of the pope, largely due to national rivalries. England and France's Hundred Years' War had just ended in 1453. Forces led by John Hunyadi (), Captain-General of Hungary, met the Turks and defeated them at Belgrade (22 July 1456). Shortly after his victory, Hunyadi himself died of a fever. On 29 June 1456, Callixtus III ordered the church bells to be rung at noon (see noon bell) as a call to prayer for the welfare of those defending Belgrade. To commemorate this victory, Callixtus III ordered the Feast of the Transfiguration to be held annually on 6 August.