In the medieval history of Europe, Bulgaria's status as the Bulgarian Empire (, Balgarsko tsarstvo ), wherein it acted as a key regional power (particularly rivaling Byzantium in Southeastern Europe) occurred in two distinct periods: between the seventh and eleventh centuries, and again between the twelfth and fourteenth centuries. The two "Bulgarian Empires" are not treated as separate entities, but rather as one state restored after a period of Byzantine rule over its territory.