Robert K. Hoffman, one of three founders of the irreverent National Lampoon magazine, has died. He was 59.

Hoffman, a noted Dallas philanthropist, died Sunday at an area hospital. He had been suffering from leukemia since December, according to his family.

He was a co-founder and managing editor of the humorous National Lampoon, spawned from the Harvard Lampoon, created while he was a student at the university.

Hoffman graduated cum laude in 1970 and received an MBA from Harvard Business School.

The magazine spun off successful films, the best known being "Animal House."

"National Lampoon never would have happened, and none of the things that came out of it would have happened, without Robert," Henry Beard, one of the other co-founders of the magazine, said in Tuesday's editions of The Dallas Morning News. "He had an exceptional pair of talents — he was extremely smart, and utterly fearless."

The third founder, Doug Kenney, died in the early 1980s.

Hoffman and his partners sold their interest in National Lampoon in 1975. He continued to serve as a trustee of the Harvard Lampoon.

Hoffman was named one of Business Week magazine's top 50 philanthropists for 2005.

A longtime art collector, he and his wife, Marguerite, in March gave 224 art objects valued at $150 million to the Dallas Museum of Art.

"I now realize the only effective method to travel and connect across time and space is art," Hoffman said in a speech he had a friend read at a March luncheon honoring the couple for their civic contributions.

Survivors include his wife, three daughters, his mother and a brother.