Katharine Hepburn and Spencer Tracy
Tracy was married, with children, and was Catholic. He couldn't allow himself to break up his family, and so he never publicly acknowledged his 27-year love affair with Hepburn. Even when she rushed to be at his side in hospital just before he died, he referred to her only as a "wonderful friend." Yet it was, for all that, a great love.
They met on the set of Woman of the Year (above) in 1942. She was a tall, sharp-voiced, Connecticut-born intellectual, he a cool, working-class mid-Westerner, seven years older. "Mr Tracy, you're a little short for me," were her first words to him. "Don't worry," he replied, "I'll cut you down to size." They fell in love during filming and became one of Hollywood's most recognisable couples. In nine films - notably Adam's Rib, Pat and Mike and Guess Who's Coming to Dinner - their verbal sparring became a form of public courtship. They kept their relationship a secret, though, avoiding the press and using the back doors of restaurants and hotels. In the last years of Tracy's life, they lived together but maintained separate homes for show. For a long time, he was an alcoholic, and used to rant abusively at her before passing out. She nursed him constantly, helped him dry out, and arranged her professional commitments around him. Yet when he died, in 1967, she didn't attend the funeral, out of respect to his wife.