Krum's campaigns Simeon I's campaigns Sviatoslav's invasion of Bulgaria Byzantine conquest of Bulgaria Uprising of Peter Delyan Second Bulgarian Empire After the beginning of the anti-Byzantine rebellion in 1185 and especially after the victory at Tryavna the Bulgarians firmly took the initiative of the war.
Ivan Asen I demanded the return of all Bulgarian lands, which he knew it was impossible for the Byzantines to accept, and continued the struggle.
In the same year, the Bulgarian army advanced deep to the south-west and reached the vicinity of Serres taking many fortresses on its way.
During the winter, the Bulgarians retreated to the north but in the next year reappeared and defeated a Byzantine army under the sebastokrator Isaac near the town.
Slightly before reaching Tarnovo, Ivan Asen I was murdered by his cousin Ivanko, who had been allegedly bribed by the Byzantines.