High Quality Content by WIKIPEDIA articles! The Middle Ages in Romania began with the withdrawal of the Mongols, the last of the migrating populations to invade the territory of modern Romania, after their attack of 1241–1242. It came to an end with the reign of Michael the Brave (1593–1601) who managed, for a short time in 1600, to rule Wallachia, Moldavia and Transylvania, the three principalities whose territories were to be united some three centuries later to form Romania.