After the defeat of Nazi Germany in World War II, its territory was incorporated into a new, larger Silesian Voivodeship which existed until 1950.

Due to efficient agricultural practices, the Silesian Voivodeship also was a major producer of food, in spite of its small size.

The rest did not feel any strong connections to either of those nations; according to Wojciech Korfanty's estimations, this last group represented up to a quarter of the total whole population of the region.

[2] The Treaty of Versailles resolved that a plebiscite be conducted so that the local population could decide whether Upper Silesia should be assigned to Poland or to Germany.

Based on the results of the plebiscite, which was held on 20 March 1921, Upper Silesia was divided between Poland and Germany.

It had been granted autonomous status by an Act of the Polish Sejm dated 15 July 1920.

[3] That status was secure until the May Coup in 1926, which started various attempts to limit it in favour of a strong and centralised state.

The territory returned to Polish possession at the end of the war, and the 1920 act giving autonomous powers to the Silesian Voivodeship was formally repealed by a law of 6 May 1945.

The voivodeship possessed wide autonomy in domestic matters excluding foreign and military policy.