The Transylvanian Diet (; ; ) was an important legislative, administrative and judicial body of the Principality (from 1765 Grand Principality) of Transylvania between 1570 and 1867. The general assemblies of the Transylvanian noblemen and the joint assemblies of the representatives of the "Three Nations of Transylvania"the noblemen, Székelys and Saxonsgave rise to its development. After the disintegration of the medieval Kingdom of Hungary in 1541, delegates from the counties of the eastern and northeastern territories of Hungary proper (or Partium) also attained the Transylvanian Diet, transforming it into a legal successor of the medieval Diets of Hungary. The diet sessions at Vásárhely (now Târgu Mureş) (20 January 1542) and at Torda (now Turda) (2 March 1542) laid the basis for the political and administrative organization of Transylvania. The diet decided on juridical, military and economic matters. It ceased to exist following the Austro-Hungarian Compromise of 1867. Background Transylvania ("Land beyond the Forests") was a borderland in the medieval Kingdom of Hungary. The development of royal administration is documented from the second half of the 11th century. The royal castle at Torda (now Turda in Romania) was first mentioned in 1075, the fortress at Küküllő (now Cetatea de Baltă in Romania) in 1177. Most royal castles developed into the seats of counties, which were important administrative units, each named for its center. A high-ranking royal official, the voivode was the superior of the ispáns (or heads) of the Transylvanian counties from the late 12th century. A separate royal official, the Count of the Székelys, lead the Hungarian-speaking Székelys from the 1220s. The Székelys had moved from other regions of the kingdom to Transylvania and formed a community of free warriors. Their administrative units were known as "seats" from the 14th century. The seats were headed by elected officials. The Székelys initially held their lands in common. However, disparity between wealthy and poor Székelys grew, enforcing royal legislation to acknowledge the existence of Székely groups of diverse status in 1473. Thereafter, only the wealthiest Székelys fought in the royal army on horse; those who could only fight as foot-soldiers started to lose their political rights. The ancestors of the Transylvanian Saxons settled in the southern and north-eastern regions in the 11th and 12th centuries. In 1224, Andrew II of Hungary granted privileges to the Saxons who inhabited southern Transylvania, putting them under the authority of a royal official, the Count of