I am not sure if this is a village, town or district, I think its near to Warsaw.
It is a town near Warsaw
but also a capital of a county with the same name
the Russian troops attacked his home murdered his grandparents and parents and that he was forced to join the cavalry and was sent to siberia, somehow he ended up in Italy
Italy is nothing unusual...but If he was deported to Siberia, It rather wasn't from Karczew as that town wasn't in Soviet occupied area.