The Asen dynasty, also called the Asenids (Bulgarian: Асеневци, Asenevtsi, Romanian: Asănești) founded and ruled a medieval Bulgarian state, called in modern historiography the Second Bulgarian Empire, between 1185 and 1280.
The Asen dynasty rose as the leaders of Bulgaria after a rebellion against the Byzantine Empire at the turn of the year 1185/1186 caused by the increase in the Imperial taxes.
Some members of the Asen family entered Byzantine service in the thirteenth to fourteenth centuries. The name also occurs as a family name in modern Greek, and could go back to the same name. Their origin is obscure.[1]