Second Bulgarian Empire (12th – 13th c.)
The rebellion of the brothers Peter and Asen in 1185 renewed the Bulgarian independence from the Byzantine Empire and resulted in the establishment of the Second Bulgarian Empire under Ivan Asen I. The latter was succeeded by his younger brother Kaloyan (1196-1207) who took advantage of the disintegration of the Byzantine Empire, conquered Macedonia and decisively defeated the Latins in the Battle of Adrianople in 1205.
The Second Bulgarian Empire joined the competition for the Byzantine succession after the fall of Constantinople during the Fourth Crusade in 1204. However, the rise of the Second Bulgarian Empire was hindered by sudden death of Kaloyan before the walls of Thessaloniki in 1207 as well as by the ambitions of local leaders who weakened the central power.