Moson County

Hungary (972 km2) Moson (German: Wieselburg, Slovak: Mošon) was an administrative county (comitatus) of the Kingdom of Hungary, situated mostly on the right (south) side of the Danube river.

Its territory is now divided between Austria and Hungary, except a small area which is part of Slovakia.

Moson is also the name of a town, nowadays part of the city Mosonmagyaróvár, 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.

Three villages – Dunacsún, (Čunovo), Horvátjárfalu (Jarovce), and Oroszvár (Rusovce) – became part of Czechoslovakia.

Győr and Moson counties after the Treaty of Trianon. In 1923, the two counties were merged to form Győr-Moson County. The map shows that small part of the former Pozsony County that remained in Hungary. (4) territory assigned from Moson County to Sopron County in 1921. (5) and (6) territory ceded to Czechoslovakia in 1947.
The formation of modern Győr-Moson-Sopron County. (1) territory assigned from Vas County to Győr-Moson-Sopron County in 1950. (2) territory assigned from Sopron County to Vas County in 1950.
Ethnic map of the county with data of the 1910 census (see the key in the description).