Ottoman Sultan Murad I was assassinated by a Serbian nobleman and knight Milos Obilic by a knife. He was the only Ottoman Sultan who died by assassination.
Murad I (29 June 1326 – 15 June 1389) was the Ottoman Sultan from 1362 to 1389. He was a son of Orhan and the Valide Nilüfer Hatun.
Murad I conquered Adrianople, renamed it to Edirne and in 1363 made it the new capital of the Ottoman Sultanate. Then he further expanded the Ottoman realm in Southeast Europe by bringing most of the Balkans under the Ottoman rule and forced the princes of northern Serbia and Bulgaria as well as the Byzantine emperor John V Palaiologos to pay him tribute. Murad I administratively divided his sultanate into the two provinces of Anatolia (Asia Minor) and Rumelia (the Balkans).
In 1389, Murad's army defeated the Serbian Army and its allies under the leadership of Lazar at the Battle of Kosovo. There are different accounts from different sources about when and how Murad I was assassinated. One Western source states that during first hours of the battle, Murad I was assassinated by Serbian nobleman and knight Milos Obilic by a knife. Most Ottoman chroniclers state that he was assassinated after the finish of the battle while going around the battlefield. Others state that he was assassinated in the evening after the battle at his tent by the assassin who was admitted to ask a special favour.