It was established following the incorporation of Trans-Olza region by Poland from Czechoslovakia on 2 October 1938.

Its seat was located in Český Těšín (then known in Polish as Cieszyn Zachodni).

Following the Munich Agreement signed on 30 September 1938, Germany incorporated the German-speaking area of Sudetenland, from Czechoslovakia.

In context of such events, on 30 September 1938, Poland demanded Czechoslovakia to cede them Polish-speaking area of Trans-Olza, which it did on 2 October 1938.

[1] The ceded area included Český Těšín District, which was subsequently renamed to Cieszyn West County, with its seat being placed in Cieszyn Zachodni.