Over most of this period, Banat, Crişana, Maramureş, 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.