Julian McMahon, known for roles in Nip/Tuck, Charmed, and as Dr. Doom in Fantastic Four, has died at 56 after a secret fight with cancer. His wife Kelly confirmed he passed away peacefully earlier this week.

McMahon’s last public appearance was in March at SXSW with Nicolas Cage. He had kept his illness private while continuing to work.

A versatile Australian-American actor, McMahon gained fame through decades of work in both television and film. His death has triggered an outpouring of grief from fans and colleagues across the globe.