In the interwar period, the Silesian Parliament (Sejm) was in the legislative authority of the autonomous Silesian voivodeship. In the years 1925-1929, a magnificent edifice was built in Katowice, which became the seat of both the Silesian Parliament and the Voivodeship Office. The building was the largest in Poland at that time. It- was built in the neo- Classicist style. The Parliament Hall became a model for the Sejm of the Republic of Poland, which was being constructed at the same time.