Legendary MMA coach and ex-competitor Jeffrey “Duke” Roufus has died at the age of 55, his business partner Scott Joffe announced on social media Friday night.

Roufus’s MMA journey took shape through kickboxing as he won multiple titles during the 1990s as a competitor.

Following his retirement from competing, Roufus became a well-known trainer as he founded Roufusport MMA academy in Milwaukee, Wisc., operating it with Joffe.

He worked with many notable names in the UFC, including former champions Belal Muhammad, Anthony Pettis, Tyron Woodley, Rose Namajunas and Jens Pulver.

“His knowledge, charisma, and passion inspired countless fighters to reach heights they never imagined possible,” Joffe said in his post.

“From world champions to first-day students, everyone who crossed his path felt his genuine care and unwavering belief in their potential … The culture he built — rooted in respect, hard work, and family — will live on through the fighters, coaches, and students who proudly carry his torch.”