At the end of the 12th century, some northern parts of Macedonia were temporarily conquered by Stefan Nemanja of Serbia. In the 13th century, following the Fourth Crusade, Macedonia was disputed among Byzantine Greeks, Latin crusaders of the short-lived Kingdom of Thessalonica, and the revived Bulgarian state. Most of southern Macedonia was secured by the Despotate of Epirus and then by the Empire of Nicaea, while the north was ruled by Bulgaria. After 1261 however, all of Macedonia returned to Byzantine rule, where it largely remained until the Byzantine civil war of 1341–1347. Taking advantage of this conflict, the Serb ruler Stefan Dushan expanded his realm and founded the Serbian Empire, which included all of Macedonia, northern and central Greece – excluding Thessaloniki, Athens and the Peloponnese. Dushan's empire however broke up shortly after his death in 1355. After his death local rulers in the regions of Macedonia were despot Jovan Uglješa in eastern Macedonia, and kings Vukašin Mrnjavčević and his son Marko Mrnjavčević in western regions of Macedonia.