The Kingdom of Bulgaria was established as an independent state when the Principality of Bulgaria, an Ottoman vassal, officially proclaimed itself independent on October 5, 1908 (September 22 O.S.). This move also formalised the annexation of the Ottoman province of Eastern Rumelia, which had been under the control of Principality of Bulgaria since 1885. In 1946, the monarchy was abolished, its final Tsar was sent into exile and the Kingdom was replaced by a People's Republic. Although rarely, it is sometimes referred to as the Third Bulgarian Empire, as in the Middle Ages the term Tsardom meant an Empire. However, the Third Bulgarian state was internationally recognized as a Kingdom.