Poland had originally been an independent kingdom but by the late 18th century it had been divided up between Russia, Austria-Hungary and Germany.

In 1914, Roman Dmowski, the main leader of the Polish nationalist movement, believed the best way to achieve a unified and independent Poland, was to support the Triple Entente against the Triple Alliance.

Jozef Pilsudski, a nationalist leader based in Galicia, disagreed and saw Russia as the main enemy. Pilsudski began building a private army that he hoped would enable Poland to fight for its independence from Russia.