 Complete the following phrase:  In the Treaty of Versailles, after the defeat of Imperial Germany and Austria-Hungary in World War I, it was decided that the population of Upper Silesia should hold a plebiscite to determine the division of the province between Poland and Germany, with the exception of a area around Hlučín Hultschiner Ländchen, which was granted to Czechoslovakia in 1920 despite it being German-speaking majority. The plebiscite, organised by the League of Nations, was held in 1921. In Cieszyn Silesia there was an interim deal between the Polish Rada Narodowa Księstwa Cieszyńskiego and the Czech Národní výbor pro Slezsko about partition of past lands of the Duchy of Cieszyn along ethnic lines. However, that deal was not approved by the Czechoslovak government in Prague. Poland held elections in the entire disputed area, and on 23 January 1919, Czech troops invaded the lands of Cieszyn Silesia, stopping on 30 January 1919 on the Vistula River near Skoczów. The planned plebiscite was not organised in the Cieszyn Silesia but was held in most other parts of Upper Silesia. On 28 July 1920, the 