 Begley was born Ludwik Begleiter in Stryi, then part of the Polish Republic and now in Ukraine, the only child of a physician.Using forged identity papers that enabled them to pretend to be Polish Catholics, he and his mother survived the almost wholly successful German attempt to kill all Polish Jews.He lived with his mother at first in Lwów, and then in Warsaw until the end of the August 1944 Warsaw uprising.