Born in Sundsvall, Lars Mortimer lived and worked in Långhed in the north of Alfta, Hälsingland. He studied art history in Uppsala, but eventually chose a profession in the field of comics in the 1970s. He began his career as an editor on the Semic comic books 91:an and Knasen between 1973 and 1978. His first comic series was 'Bobo', that had its own magazine from 1978 to 1989, as well as a spin-off series called 'Gnuttarna'.
Mortimer subsequently worked with the Brit Des Cox on 'Vattenhålet' ('Waterhole'), a series about two hippo ladies published in Lilla Fridolf in the early 1990s and in a series of albums by Egmont. His best known creation however is the moose 'Hälge', that first appeared in the newspapers Svensk Jakt and Åsa Nisse in 1991. The strip has since then appeared in several daily and evening newspapers, including Aftonbladet, and from 2000 also in its own monthly comic book
