Battle of Ostrovo

In 1040, Peter Delyan led an uprising against the Byzantines and was proclaimed tsar of Bulgaria. He successfully liberated the western Bulgarian lands from Belgrade to Larissa. Despite this period of success, the following year Peter Delyan was betrayed by his cousin Alusian. On 10 June, Peter Delyan was blinded and betrayed by Alusian, who then fled to Constantinople. This turn of events recalled earlier Byzantine attacks on the southwestern Bulgarian lands. Once again, the Byzantines chose the route through Vodena, directing their attack through Ostrovo–Lerin–Bitola, along the route now followed by the Thessaloniki–Skopje railway.

The rebels lost the battle, and the lands were reconquered by the Byzantine Empire. Tsar Peter II was captured in Constantinople.