King Matthias Corvinus of Hungary (1458–1490) was one of the most prominent figures of the period, directing campaigns to the West, conquering Bohemia in answer to the Pope's call for help against the Hussite Protestants. Also, in resolving political hostilities with the German emperor Frederick III of Habsburg, he invaded his western domains. Matthew organized the Black Army of mercenary soldiers; it was considered as the biggest army of its time. Using this powerful tool, the Hungarian king led wars against the Turkish armies and stopped the Ottomans during his reign. After the death of Matthew, and with end of the Black Army, the Ottoman Empire grew in strength and Central Europe was defenseless. At the Battle of Mohács, the forces of the Ottoman Empire annihilated the Hungarian army and Louis II of Hungary drowned in the Csele Creek while trying to escape. The leader of the Hungarian army, Pál Tomori, also died in the battle. This is considered to be one of the final battles of Medieval times.