Ivan Asen II of Bulgaria

Ivan Asen II (Bulgarian: Иван Асен II, pronounced [iˈvan ɐˈsɛn ˈftɔri]; also Йоан Асен II, Yoan Asen II;) in English sometimes known as John Asen II, ruled as Emperor (Tsar) of Bulgaria from 1218 to 1241, during the Second Bulgarian Empire.

Early rule

He was a son of Ivan Asen I of Bulgaria and Elena (religious name Evgenija). Elena, who survived until after 1235, is sometimes alleged to be a daughter of Stefan Nemanja of Serbia, but this relationship is questionable and would have caused various canonical impediments to marriages between various descendants. Ivan Asen II's father was one of the two founders of the Asen dynasty and the Second Bulgarian Empire. Under Ivan Asen II's rule, the empire would become the dominant force in the Balkans for about a decade, 1230–1241.

After the death of his uncle Kaloyan in 1207, Ivan Asen's cousin, Boril, usurped the throne and forced him to flee to the Rus principality of Galicia-Volhynia. With its support Ivan Asen returned to Bulgaria in 1218 to successfully overthrow his cousin and be crowned as emperor. Having established himself on the throne, Ivan Asen II set about recovering the losses sustained by Bulgaria during the reign of Boril.