Born in Norway and raised in Denmark, Jensen became a member of the Helsingør chapter of the Hells Angels, led by Michael Garcia "Lerche" Olsen, during the 1980s. Olsen had previously been president of the Copenhagen chapter, but left that post in 1985 as a result of an internal dispute within the club. Initially, an attempt was made to resolve the disagreements by allowing Olsen to head the newly-formed Helsingør chapter. The arrangement did not last, however, and the following year, the chapter was disbanded and Olsen was expelled from the club. After the dissolution of the Hells Angels in Helsingør, Jensen became associated with the biker community across the Øresund strait in Sweden. Initially, he was a member of the White Trash MC in Scania, where he had the role of leader and organizer in collaboration with Michael Ljunggren. At the time, the White Trash's ambitions were moving toward admission into the Hells Angels. The club disbanded following a police operation which resulted in Ljunggren's imprisonment, and both Jensen and Ljunggren later joined the newly-founded Morbids MC in 1991. The Morbids were offered a path to Hells Angels membership on the condition that they merge with the Rebels MC, a rival biker group with whom they had previously clashed. Rejecting the offer, they instead aligned with the Bandidos, whose only chapters in Scandinavia at the time were in Zealand. Jensen formally moved to Sweden in 1993, residing at an address in Vallåkra near Helsingborg. The Morbids became a probationary Bandidos chapter in January 1994 before formally patching over on 28 January 1995. The Morbids' refusal to capitulate to the larger Hells Angels was part of a chain of events that led to the beginning of the Nordic Biker War. Michael Garcia Olsen became president of the Bandidos' Helsingborg chapter, which was based out of a dairy farm-turned-clubhouse in nearby Kattarp, following the murder of Michael Ljunggren in July 1995.