9 March 1943 – Robert James Fischer born at Michael Reese Hospital in Chicago, Illinois, USA. His mother, Regina Wender, was a naturalized American citizen of Polish Jewish descent, born in Switzerland but raised in St. Louis, Missouri. Fischer's birth certificate listed Wender's husband, Hans-Gerhardt Fischer, a German biophysicist, as Fischer's father. The couple married in 1933 in Moscow, the Soviet Union, where Wender was studying medicine. Regina Fischer returned to the United States in 1939, while Hans-Gerhardt Fischer never entered the United States. Paul Neményi, a Hungarian Jewish physicist, may have been Fischer's biological father. Regina and Nemenyi had an affair in 1942, and he made monthly child support payments to Regina.[1] Later, Bobby Fischer was World Chess Champion (1972–1975).[2]