William began playing the electric bass at 12. He was, by the time, a huge fan of Steve Harris. Shortly afeter, he formed "Flesh and Blood", a heavy metal band with which he released an album intitled " Inferno ". In 1998, he founded Darkrise with Nico, Luke and Yann.

Between 2001 and 2005, he attended a course at the Conservatoire de Montreux and earned a degree in Jazz theory. Then, he joined the group "Near Death Condition" in 2010, with which he recorded a song on their album "The Disembodied".

In 2011, he joined the Brutal Death Metal band "Sound of Fury".