Career
He is also known by his Breton language pseudonym Jean-Yves Keraudren. Jeusset later joined with fellow nationalist extremists Gwilherm Berthou and Célestin Lainé to found Kentoc"h Mervel (Sooner Death), a group dedicated to direct action. Lainé, however, insisted that a more tightly organized group was necessary, going on to create the terrorist cell Gwenn ha du.
After Gwenn ha du performed its first violent act, blowing up a sculpture, Jeusset was one of six nationalist militants who were arrested and detained.
Jeusset was later associated with Olier Mordrel who founded the Breton National Party on the model of the Nazi party. Jeusset eventually joined Lainé"s Bezen Perrot militia, which was affiliated to the Steamship Captured after the war, Jeusset was sentenced to forced labour for life.
In 1965 he published an autobiographical memoir: A Contre-courant (Against the Current).