The Second Battle of Kosovo takes place between a Hungarian-led Crusader army and the Ottoman Empire at Kosovo field. The three-day battle resulted In the Ottoman army under the command of Sultan Murad II defeating the Crusader army of regent John Hunyadi.
After the battle, the path was clear for the Turks to conquer Serbia and the other Balkan States. With the end of the half-century-long Crusader threat to their European frontier, Murad's son Mehmed II was free to lay siege to Constantinople in 1453.