Karl Stig-Erland "Stieg" Larsson was a Swedish writer, journalist, and activist, best known for his Millennium trilogy of crime novels. These novels gained international acclaim and were published posthumously, starting in 2005, following his sudden death from a heart attack. Larsson's work spanned a variety of themes, including socialist politics and the independent research of right-wing extremism.

Throughout his life, Larsson was a fervent advocate against injustice, documenting and exposing Swedish extreme right and racist organisations through his journalistic work. At the age of 15, a pivotal moment occurred when he witnessed a rape and was unable to intervene. This event profoundly influenced his writing and activism, leading him to create stories that often highlighted societal flaws and injustices.

Despite his untimely death at the age of 50, Larsson's legacy lives on through the Millennium series, with his novels being adapted into films both in Sweden and the U.S. By March 2015, the series had sold 80 million copies worldwide, cementing Larsson's place as the second-best-selling fiction author in 2008. The final novel in his original trilogy, The Girl Who Kicked the Hornets' Nest, became the bestselling book in the United States in 2010.