The Uprising of Asen and Peter

The Bulgarian state had been under Byzantine rule since 1018. In 1185, the Byzantine Empire experienced political instability and military setbacks. To replenish his depleted treasury, the emperor imposed an additional tax on the Bulgarian population. This gave the brothers Asen and Peter the opportunity to lead the discontented Bulgarians. The uprising began on 26 October 1185. In 1186, Emperor Isaac II Angelos decided to suppress it and sent a large army. This forced Asen and Peter to withdraw north of the Danube. In 1187, the uprising gained an organised character, and after the siege of Lovech Fortress the emperor was forced to conclude a truce with the brothers.

Through the truce concluded in 1187, the Byzantine emperor effectively recognised the restoration of the Bulgarian state north of the Balkan Mountains. The Byzantine Empire succeeded in organising internal conspiracies in which Asen and Peter were murdered. Their youngest brother, Kaloyan, then ascended the throne, was proclaimed tsar and ruled from 1197 to 1207.