Additionally, in medieval times there were other lands known by the name 'Vlach' (such as Great Vlachia, situated between Thessaly and the western Pindus mountains, originally within the Byzantine Empire, but after the 13th century autonomous or semi-independent; White Wallachia, a Byzantine denomination for the region between the Danube River and the Balkans; Moravian Wallachia, a region in south-eastern Czech Republic).