The Middle Ages in Romania began shortly after the withdrawal of the Roman legions from the former Roman province of Dacia in the late 3rd century and with the start of the Early Middle Ages and the Migration Period that followed afterwards respectively. It subsequently came to an end with the reign of Domn Michael the Brave (1593–1601) who managed, for a short time between 1599 and 1600, to rule Wallachia, Moldavia, and Transylvania together, the three principalities whose territories were to be united some three centuries later to form modern and contemporary Romania.

Over most of this period, Banat, Crișana, Maramureș, and Transylvania – now regions in Romania to the west of the Carpathian Mountains – were part of the Kingdom of Hungary. They were divided into several types of administrative units, such as "counties" and "seats". The heads of the Transylvanian counties or "counts" were subordinated to a special royal official called voivode, but the province was seldom treated as a single unit, since the Székely and Saxon seats were administered separately. In the kingdom, Romanian peasants, being Orthodox, were exempt from the tithe, an ecclesiastical tax payable by all Roman Catholic commoners. However, Romanian noblemen slowly lost the ability to participate in political life, as the 14th-century monarchs pursued a zealous pro-Catholic policy. Their position became even worse after 1437 when the so-called "Union of Three Nations", an alliance of the Hungarian noblemen, the Székelys, and the Saxons, was formed in order to crush the Bobâlna peasant uprising. (Full article...)