TUCSON, Ariz. (AP) — Michael Blake, the writer whose novel "Dances With Wolves" became a major hit movie and earned him an Academy Award for the screenplay, has died.

Blake, 69, died Saturday in Tucson, Arizona, after a long battle with cancer, his business partner, Daniel Ostroff, said.

Blake, who wrote several novels, is best known for "Dances With Wolves," which he wrote while broke at the urging of his longtime friend, the actor Kevin Costner. The novel was fairly unsuccessful, but it became a film after Costner asked Blake to adapt it into a movie. The book went on to sell 3.5 million copies after the success of the movie.

"Dances With Wolves," a Civil War epic about Army lieutenant who befriends a Native American tribe, won seven Academy Awards, including one for Blake for best adapted screenplay.

Despite his success, Blake was a humble man who passionately advocated for many causes, including literacy, Native American history and the disappearing of wild horses in the West, said his wife, Marianne Mortensen Blake.

"Well, he was probably one of the most generous people I've ever met. He was definitely one of the toughest guys I've ever met," Mortensen Blake said.

The couple met through the actor Viggo Mortensen, a close friend of Blake's and Mortensen Blake's cousin. They married in 1993 and have three teenage children, all named after Native Americans that the couple admires. Blake is also survived by his brother, Daniel Webb.

Mortensen Blake described her husband as a loving father who dedicated his life to helping others.

Blake was born in North Carolina and lived with his family in Texas before settling in southern California. He attended the University of New Mexico, but he left before graduating. The university now has an archive of his work at the student newspaper and other writings, Ostroff said.

Ostroff met Blake in 1988 and has worked with him on several occasions. He and Mortensen Blake are now bringing to life the sequel to "Dances With Wolves," a novel Blake wrote called "The Holy Road."

"In my experience, great visionary writers like Michael are often ahead of Hollywood and ahead of the audience by a generation. I think the best Michael Blake film adaptations are yet to come," Ostroff said.

Blake spent several years living out his car and on friends' couches while he wrote the "Dances With Wolves" novel.