12. – Bulgaria at the time of Assen I and Kalojan.

The first heavy armed blow against the rulership of Byzantium was the revolution raised in 1186 bv the brothers Assen and Peter in north Bulgaria. After a two-year struggle, powerfully led against the Byzantine yoke, they established in 1187 the political and ecclesiastical independence on Bulgaria, and Assen's election to the throne laid the foundation of the second Bulgarian Empire, with Tirnowo as capital. During his nine-years reign (1187-1196), Assen I who also took up the fight against Byzanztium, this time with the aim of delivering and uniting all Bulgarian territories, succeeded in delivering nearly the whole north Bulgaria, and the district of Sofia as well as all provinces south of the Balkan mountains, and the Sredna Gora (northern Thracia). At the end of his reign he directed the liberation-movement along the Struma valley, to Macedonia, but, falling victim to assassination, he could not confirm his power there.

His work, however, was taken up again by his brother and successor to the throne, Ka1ojan (1197-1207). This czar understood to benefit from the tragic events, happening to the Byzantine Empire – the conquest of Constantinople by the crusaders, the fourth crusade, and the establishment of the Latin Empire on the Balkan peninsula. The crusaders being still engaged in the siege of Constantinople, Kalojan in a short space of time, could annex nearly all the Bulgarian Balkan districts: the Morawaland in the west (the Branitschewo district and Belgrade) and Macedonia close to the Bistritza river in the south-west. The uninterrupted wars that soon after began against the Latins and the Greeks, enabled him also to occupy all south-Bulgarian territories, including the city of Ser (Serres). Kalojan, however, could not follow up his plan to eject the Latins from the Balkan peninsula and conquer Constantinople. Like his brother he was assassinated, in 1207 during the siege of Salonica.

Ths map shows Bulgaria, delivered by czar Assen 1, and enlarged by his brother Kalojan.