Pierre Le Guen started out working for the magazine O.K. after winning a contest held by this magazine in 1946. Between 1947 and 1949 he made his professional debut with the series 'Tangor'. He also cooperated on the second series of Pic et Nic, and worked as the assistant of René Brantonne for a while. In 1950 he joined the team of Vaillant. For this magazine, he created 'Jacques Flash' with Jean Ollivier (1956-59) and took over series like 'Hourrah Freddi' (1950-53) and 'Nasdine Hodja' (1953-69). He was also present in Coq Hardi and Mireille, producing 'L'Orpheline du Cirque' with a script by Jacques François (Marijac) from 1953, as well as in Pierrot with 'Envoyé Spécial' (script by Lucien Bornert).