Lenino

Polish T-34 picture in Museum of Polish Army. I don't know who painted it.

EDIT: I found a reproduction of this picture in some book. It was painted by Michał Bylina and presents soldiers of People's Army of Poland (Ludowe Wojsko Polskie) charging at Lenino with support from T-34/76, an early version of this tank with 76,2 mm gun. It was a part of 1st Warsaw Tank Regiment (1. Warszawski Pułk Czołgów), which had about 34 T-34/76s during its carieer. During the battle the Polish forces had lost 502 soldiers, 1776 were wounded and 663 missing or captured.
During the communists regime in Poland the date of the battle - October 12th - was celebrated as Polish Army Day (now it's August 15th, the date of Miracle at the Vistula) and it was often mentioned in propaganda as the sealing of Polish-Soviet brotherhood. Now it's often seen as an unnecessary massacre.