George Tyssen Butler, a documentary filmmaker best known for co-directing the 1977 feature “Pumping Iron,” died on Oct. 21 of pneumonia at his home in New Hampshire. He was 78 years old.

Butler’s death was confirmed to Variety by his longtime companion Caroline Alexander.

Butler was born in England in 1943 and grew up in Somalia and Jamaica. He graduated from the Groton School in Massachusetts before earning a bachelor’s degree in English at the University of North Carolina and a master’s in creative writing from Hollins College. Butler became involved in the world of bodybuilding in the early 1970s by photographing competitions for Life magazine and The Village Voice.

Collaborating with author Charles Gaines, the pair penned a book about the culture of bodybuilding. The success of “Pumping Iron: The Art and Sport of Bodybuilding” led to the making of the documentary “Pumping Iron,” for which Butler and Gaines wrote the script. Butler also co-directed the film with Robert Fiore.

Centering on the 1975 Mr. Olympia competition, “Pumping Iron” was a landmark look into the world of bodybuilding and launched the film career of Arnold Schwarzenegger, helping make the five-time Mr. Universe winner a household name. “The Incredible Hulk” star Lou Ferrigno is also a subject in the documentary. Butler helmed “Pumping Iron II: The Women,” a follow-up focusing on female bodybuilding, in 1985.

“‘Pumping Iron,’ the book and the movie, drew the general public in to our strange little niche sport and brought fitness – and this Austrian with an unpronounceable name and a funny accent – to the masses,” Schwarzenegger wrote in a statement on Twitter. “I was saddened to hear of George’s passing. He was such a talent, he had a fantastic eye and he was a force for the sport of bodybuilding and the fitness crusade.”

Butler also established his own film company, White Mountain Films, in 1972, and produced many documentaries over the years focusing on a variety of subjects. He directed the 2004 documentary “Going Upriver,” focusing on his friend and then-presidential candidate John Kerry. Most recently, he served as producer and director of “Tiger Tiger,” an IMAX documentary that follows the late big-cat conservationist Alan Rabinowitz, set to be released next year. Butler worked on the film with his friend and collaborator, Frank Marshall.

In addition to filmmaking, Butler was a lifelong photographer whose subjects included inner city Detroit, Jamaica and personalities such as Kerry and Schwarzenegger. He was also a dedicated conservationist and woodsman, directing and producing ecologically-minded docs such as “The Lord God Bird” and “In the Blood.”

Butler is survived by Alexander, his two sons, his six grandchildren and his brother, Richard.