The Siege of Belgrade, one of the greatest crusade wars of medieval times takes place in Belgrade as Sultan Mehmed II besieges the city with 150,000 soldiers and over 100 ships. Joint Hungarian and Serbian troops, aided by other Christian nations, repel the Ottoman forces. Pope Calixtus III praises Belgrade and its defender John Hunyadi as the Saviors of Christianity. Catholic Belgrade is now the only bastion of Christianity in the Balkans.