Espé was born Sébastien Portret in Mazamet, Tarn, in 1974. He pursued a scientific direction while at high school, but eventually ended up at the School of Fine Arts in Toulouse. He created the fanzine Broute and got acquainted with several artists from the area, such as Aris. He first used his pseudonym Espé when he worked as a stringer for the musical magazine Groove.
After obtaining his degree, he worked in industrial design for a while, but eventually returned to comics. He cooperated on some collective albums published by Petit à Petit and Delcourt between 1999 and 2003. He has worked with writer Éric Corbeyran on several comic series, starting with the horror series 'Le Territoire' (Delcourt, 2003-2008). They continued their cooperation with 'Le 3e Oeil' (Delcourt, 2008-09), a comic adaptation of the Marc Levy novel 'Sept jours pour une éternité...' (Casterman, 2010-11), an installment in Frank Giroud's series 'Destins' (Glénat, 2010) and 'Châteaux Bordeaux' (Glénat, 2011).