Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

By a referendum that may have been rigged, the residents of Sopron decided in 1921 not to join this country, which was later led by a priest named Ignaz Seipel. A plebiscite in 1920 allowed this country to retain its province of Carinthia; that vote had been required by the Treaty of Saint Germain. Its parliament was disbanded in 1933 by Engelbert Dollfuss, who was assassinated by Nazi agents in 1934 a few months after clashes fighting broke out in Linz. For 10 points, name this country that was annexed to Germany via the Anschluss.
History