Ivan Asen's father, Ivan Asen I, was one of the two leaders of the great uprising of the Bulgarians and Vlachs against the Byzantine Empire in 1185. The nomadic Cumans, who dwelled in the Pontic steppes, supported the rebels, enabling them the restoration of the Bulgarian Empire. The empire initially encompassed the Balkan Mountains and the plains to the north of the mountains as far as the Lower Danube. Ivan Asen I was styled "basileus" (or emperor) of the Bulgarians from around 1187. His son and namesake was born between 1192 and 1196. The child's mother was called Elena, "the new and pious tsarina" (or empress), in the "Synodikon of Tzar Boril".