Norma Jeane Mortenson, who would become better known around the world as the glamorous actress Marilyn Monroe, was born on June 1, 1926, in Los Angeles, California. She was later given her mother’s name and baptized Norma Jeane Baker. At the outset of her acting career, Norma Jeane dyed her brown hair blonde and changed her name again, calling herself Marilyn Monroe (Monroe was her grandmother’s last name). Her true breakout performance came in Niagara (1953), a thriller in which Monroe played an adulterous young wife who plots with her lover to kill her husband.

Source: History.com