While the two Empires were facing enormous internal difficulties, the Serbs took the favorable opportunity to expand its domain. During the civil war in Byzantium in 1320s and 1330s, the Serbs conquered most of the Bulgarian and Aromanian populated Macedonia from the Byzantines. In 1330 Serbian forces defeated Bulgarian ones, led by Emperor Michail Shishman at Velbazhd effectively raising the country to the status of the most powerful state in the region. In 1346, Serbian king Stefan Uroš IV Dušan received the title of Emperor with the blessing of the Bulgarian Emperor Ivan Alexander, although after his death in 1355, the large Serbian Empire disintegrated into a few independent states. In Bulgaria of the same period Ivan Sratsimir inherited Vidin from his father Ivan Alexander in 1356, while despot Dobrotitsa – nominally his subject – ruled Dobruja. Lack of stability was eminent in the southern Balkans as well: in 1341–1347 the Byzantine Empire was shaken by a bloody civil war between John V Palaiologos and John VI Kantakouzenos.