Udvarhely county consisted of three former
seats of the
Székelys:
Udvarhelyszék, Bardóc and Keresztúr (the latter two as filial seats of the former). It was formed in 1876, when the administrative structure of Transylvania was changed. In 1920, by the
Treaty of Trianon, the county became part of Romania until 1940 when, by the
Second Vienna Award, much of its territory was reassigned to Hungary. After the end of
World War II it became again part of Romania. Most of its territory lies in the present-day Romanian county of
Harghita, with small parts in
Mureș (a small part in the west) and
Covasna (a small part in the south-east). ==Demographics==