Stieg Larsson was a Swedish writer, journalist, and activist. He is best known for his posthumously published Millennium trilogy of crime novels, which have since been adapted into films. The first novel in the trilogy, 'The Girl with the Dragon Tattoo', was published in 2005 and has since become a worldwide phenomenon. Larsson's other works include non-fiction books about social issues and investigative journalism. He died in 2004 at the age of 50.