William Vance studied at the Academy of Fine Arts in Brussels and worked in the advertising industry. The first steps as a cartoonist he started as an assistant to Dino Attanasio. He got a job in Tintin, where he worked as an illustrator and his first short stories and series drew. With Greg the spy series Bruno Brazil emerged.
In 1967 the Belgian women's magazine Femme d' Aujourd'hui urgently needed a replacement artist for the currently running episode of Bob Morane, he jumped a short term and eventually took on the adventure series. The Femme d' Aujourd'hui cooperation with lasted until 1983 and brought more series like the seafaring adventure Bruce J. Hawker forth.
He celebrated his biggest success with the spy series XIII, which he designed in collaboration with Jean Van Hamme. Among his most important employees included his wife Petra as a colourist, his brother René Follet and Felicísimo Coria. He lives in Spain and went into retirement in 2010, when the first signs of Parkinson's disease became noticeable.