An avid comics fan since his childhood, Alain Henriet took evening courses in comic art from Philippe Foerster and Gérard Goffaux during a period of three years. He then enrolled in the Academy of Fine Arts in Liège, while contributing his first artwork to the shortlived magazine Brazil. Together with Baloo, he contributed short stories to L'Inédit and this magazine's publisher also published their first black-and-white comic book, 'Une pizza à l'oeil', in 1996. He won a contest held by Spirou and also worked at this magazine's editorial offices as an intern, before being employed there as a corrector in 1998.
He created the first book in the series 'Le Portail' with Olier in 1998. It wasn't until 2003 that the second installment was published by Points Images, since the original publisher (Le Téméraire) had gone bankrupt. In 2000, he resumed his collaboration with Baloo and revived the character from their first book in 1996, resulting in the 'John Doe' series in Delcourt's Sang Froid collection (2001-02). Henriet subsequently teamed up with Daniel Pecueur in 2003 to launch the 'Golden Cup' series for Delcourt 2003. Henriet has furthermore drawn an installment in the 'Pandora Box' series in 2005, created the detective series 'Damocles' with Joël Callède for Dupuis in 2008, and the historical aviation series 'Dent d'Ours' with Yann for Dupuis in 2013.