During the Middle Ages Romanians were mostly known as Vlachs, a blanket term ultimately of Germanic origin, from the word Walha, used by ancient Germanic peoples to refer to Romance-speaking and Celtic neighbours. Besides the separation of some groups (Aromanians, Megleno-Romanians, and Istro-Romanians) during the Age of Migration, many Vlachs could be found all over the Balkans, in Transylvania, across Carpathian Mountains as far north as Poland and as far west as the regions of Moravia (part of the modern Czech Republic), some went as far east as Volhynia of western Ukraine, and the present-day Croatia where the Morlachs gradually disappeared, while the Catholic and Orthodox Vlachs took Croat and Serb national identity.