Richard Griffiths, the British actor best known for playing Vernon Dursley in the Harry Potter films died on Thursday. He was 65.

Griffiths died at the University Hospital in Coventry, England. After undergoing heart surgery, the actor began to suffer from complications that ultimately caused his death, according to his agent, Simon Beresford.

Daniel Radcliff, who played the title character in the adaptation of J.K. Rowling’s novels, issued a statement regarding the loss of his former castmate.

"Richard was by my side during two of the most important moments of my career," Radcliffe said in the statement. "In August 2000, before official production had even begun on Potter, we filmed a shot outside the Dursleys', which was my first ever shot as Harry. I was nervous and he made me feel at ease. Seven years later, we embarked on Equus together. It was my first time doing a play but, terrified as I was, his encouragement, tutelage and humor made it a joy. In fact, any room he walked into was made twice as funny and twice as clever just by his presence. I am proud to say I knew him."

Griffiths was born in Thormaby-on Tees in England. There, he was raised by parents who were both deaf and mute. Developing a knack for creative expression, Griffiths eventually imparted on a decade-long stint with the Royal Shakespeare Co. He then went on to earn roles in Withnail and I, Gandhi, Hugo and of course, the Harry Potter movies.

Griffiths, who won a Tony Award for his acting in The History Boys, had last taken the stage in The Sunshine Boys in London’s West End. He was due to reprise his role in Los Angeles later this year alongside Danny DeVito.

Griffiths is survived by his wife, Heather Gibson.