Kaloyan of Bulgaria

Kaloyan or Kalojan, also known as Ivan I, Ioannitsa or Johannitsa, the Roman-Slayer, was emperor or tsar of Bulgaria from 1196 to 1207. He was the younger brother of Theodor and Asen, who led the anti-Byzantine uprising of the Bulgarians and Vlachs in 1185. The uprising ended with the restoration of Bulgaria as an independent state. He spent a few years as a hostage in Constantinople in the late 1180s. Theodor, crowned Emperor Peter II, made him his co-ruler after Asen was murdered in 1196. A year later, Peter was also murdered, and Kaloyan became the sole ruler of Bulgaria.