The Warsaw Uprising began 01.08.1944. It was struggle to liberate capital of Poland, Warsaw from German occupation before Soviets arrive. Uprising was intended to last for only few days, but Red Army stopped near city and didn't supported Uprising. Despite of heroism of soldiers and civilians, Polish forces were forced to capitulate after 63 days. About 120000 people were killed and 85% of city was destroyed.
To celebrate 64 anniversary Polish band Armia (check this post) recorded two covers of songs from Warsaw Uprising. Those song were released on band's official forum. Now You can check them.
Website about Warsaw Uprising (in English)
Armia "Warszawskie dzieci / Pałacyk Michla" 
1. Warszawskie dzieci / Children of Warsaw [02:24]
2. Pałacyk Michla / Michl's Palace [02:39]