Ivan II (Иван II, also Йоан II, Ioan II, ), known as Kaloyan the Greek-slayer or alternatively as the Roman-slayer , ruled as emperor (tsar) of Bulgaria between 1197 and 1207. He is the third and youngest of the brothers who managed to restore the Bulgarian Empire, the others being Peter IV and Ivan Asen I. Kaloyan managed to stabilize the tsar's power and the Second Bulgarian Empire's position as a leading power in Southeastern Europe thanks to his successful campaigns against the Latin Empire.