From my knowledge of Lithuanian and Polish history I know that Poland united with Lithuania in 1386AD and they defeated the Teutonic Knights at Grunwald in 1410AD. The joint monarchy survived many upheavals but eventually went into decline, which ended with the third and final partition of Poland by Prussia, Russia, and Austria in 1795. At one stage the old Lithuanian capital of Vilnius was under Polish rule.
There are a lot of Polish communities, shops and restaurants throughout Australia. There was a famous film called Pan Tadeuz.