During the Mongol invasion of Poland, southeastern Polish city of Sandomierz was regarded by the invaders as a strategically important location, which had to be captured.
Sandomierz lies near the confluence of the Vistula and the San rivers, near the 13th-century border between the Kingdom of Poland and Mongol-controlled Red Ruthenia.
A great number of residents of the area was massacred, and the invaders saved only young men, whom they enslaved.
During the siege, the Mongols used specially designed engines, especially stone throwing machines, which threw rocks weighing over 100 kilograms.
The city was captured after four days, and after the sack, Mongol forces headed westwards, to Wiślica and Skalbmierz.