Until the end of World War I, it was the seat of Kismarton district in Sopron county in the Kingdom of Hungary. Without plebiscite, the city and the entire Hungarian territory of Burgenland (with the exception of the city of Sopron and 11 other villages where referendums were held) was annexed to Austria by the Saint-Germain and Treaties of Trianon in 1921. Since 30 April 1925, Eisenstadt has been the seat of the Burgenland state government and thus the state capital. During World War II, Eisenstadt was heavily bombarded. On 2 April 1945, it was captured by Soviet troops of the 3rd Ukrainian Front in the course of the Vienna Offensive, and the city remained under Soviet occupation until 1955. In 1960, Eisenstadt became the see of its own Roman Catholic diocese.