He became a lawyer, then a journalist, and a businessman. He owned a garage in Liverpool from 1898, then a second in Paris from 1905. A
delegate of the
Automobile Club de France (fr), he organized motor races, contributed to the newspaper ''L'Auto
(fr), and wrote technical books, including the 1907 book, A.C.F. History of the Automobile
, and the French-English Automobile Dictionary'' in 1910. In 1909, already a published author, Souvestre co-wrote, with his friend and assistant Allain, their first novel,
Le Rour.
Investigating Magistrate Germain Fuselier, later to become a recurring character in the
Fantômas series, appears in this first novel. In February 1911, Allain and Souvestre began the
Fantômas book series at the request of Joseph-Arthème Fayard
(fr), a publisher, who wanted to create a new monthly
pulp magazine. Allain and Souvestre also jointly wrote the spy series ''Naz-en-l'air
. After his death, Allain continued the Fantômas'' saga alone. == Private life ==