The Principality of Khachen was a medieval Armenian principality on the territory of historical Artsakh (present-day Nagorno-Karabakh). The marches of Artsakh and Utik were attached to the Kingdom of Armenia in Antiquity but in the early medieval period were often under Georgian and Albanian control under Sassanid or Arab suzerainty. From the 12th century the Armenian Khachen principality dominated the region. The Byzantine emperor Constantine VII addressed his letters to the prince of Khachen with the inscription "To Prince of Khachen, Armenia."