The Moson comitatus arose as one of the first comitatuses of the Kingdom of Hungary. In 1920 by the
Treaty of Trianon a tiny part of Moson county close to
Pressburg (Pozsony, today's
Bratislava) became part of newly formed
Czechoslovakia. The eastern part stayed in Hungary and merged with
Győr county and a very small part of
Pozsony county to form Győr-Moson-Pozsony county. The western part became part of the new
Austrian land
Burgenland (formed in 1921). Three villages – Dunacsún, (
Čunovo), Horvátjárfalu (
Jarovce), and Oroszvár (
Rusovce) – became part of Czechoslovakia. After
World War II, Győr-Moson-Pozsony county merged with
Sopron County to form Győr-Sopron county. This county was renamed to
Győr-Moson-Sopron county in the early 1990s. ==Demographics==