Rodin was turned down three times by the École des Beaux-Arts and spent years working as a craftsman for other sculptors. His first major work, The Age of Bronze, was so lifelike that critics accused him of casting it from a living model.
In 1880 he was asked to make a door for a planned museum. He worked on The Gates of Hell for the rest of his life, and figures from it, such as The Thinker, became famous on their own.
Source: Wikipedia