20 mar 1921 ano - Silesia Plebiscite

Descrição:

https://en.wikipedia.org/wiki/Upper_Silesia_plebiscite

Piece of land in dispute between the Weimar German and Polish ethnicities inhabiting it.
Plebiscite (vote), decided in favour of Germany, but certain minority areas got a Polish majority as well.
Decision was given over to League as per Treaty of Versailles, who decided on a border.

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