Stieg Larsson was born in Västerbotten in northern Sweden in 1954. At the time of his birth, his parents were too young and too poor to keep him, so he was raised by his grandparents in a small village in the north of Sweden. Stieg's grandfather, Severin Boström, became the male role model for the young Stieg. Severin was strongly anti-fascist (and during the Second World War he was imprisoned in the work camp in Storsien for his anti-Nazi opinions)*. Had he been Danish, he would no doubt have been placed in a German Concentration Camp. The fate of his grandfather deeply affected and shaped Stieg's character. He wanted to protect equal rights and fight for democracy and freedom of speech in order to prevent history, and what happened to his grand father, from repeating itself.
* Stieg's father, Erland Larsson, says to stieglarsson.com that nobody in the family can confirm the information about the camp.
When Stieg was nine years old, his grandfather died and he moved to live with his parents and his younger brother. Stieg was given a typewriter for his 12th birthday, and he spent most nights of his youth staying up writing, keeping his family awake with the drumming sound. At 18 years of age he met Eva Gabrielsson at an anti-Vietnam War meeting in Umeå. Eva was to become his life long companion. With some short exceptions, mainly due to the fact that Stieg was sometimes too obsessed with his work, they lived together until Stiegs death the 9th November 2004. After his military service, Stieg travelled in Africa and has been described as "an early backpacker". He rarely had enough money on his travels, in an interview with Norra Västerbotten in 2006, his father describes how he had to work as a dishwasher and sell his clothes to afford a ticket home from Algeria.
Stieg Larsson was also interested in Science Fiction. Among other things was he the chairman of the Scandinavian science fiction society and published two magazines.
During the last 15 years of his life, he and his life companion Eva Gabrielsson lived under constant threat from right-wing violence. When a labor-union leader was murdered in his home by neo-Nazis in 1999, the police discovered photos of and information about the couple in the murderer's apartment. So it was not without reason that the couple took precautionary measures. They were never seen together outside the house, they moved mirrors in the hall and they always kept the blinds down. Those are just a few examples. Stieg was an expert in the area, and wrote a book of instructions on how journalists should respond to threats for the Swedish Union of Journalists ("Överleva Deadline", 2000).
The situation created a contrast between Stieg's work at Expo and his night-time novel writing. He regarded his writing of detective novels as relaxing. Keeping track of loose ends, characters and made up conspiracies posedno problem since it was, after all, fiction and no one would threaten either Eva or himself because of it.