Tvrtko had accepted the necessity of defending Christian Europe on his shoulders and dispatched the best squadrons of his military under the Duke Vlatko Vuković to fight in the Serbian Army of Prince Lazar Hrebeljanović in the epic Battle of Kosovo on 15 June 1389. Tvrtko cherished the battle as his personal success, claiming that he had defended Europe and Christianity in the name of the Christ against the infidel soldiers that threaned the civilized world. He dispatched the news across to western Europe and described how 12 Serbian noblemen managed to break through the Ottoman ranks to Sultan Murad and kill him.