University of Wisconsin graduate and famed historian Stephen Ambrose died of lung cancer Sunday at 66.

Ambrose graduated from UW with a degree in history in 1957 and went back to obtain his Ph.D. in 1963. He spent most of his career teaching at the University of New Orleans, but late in his life became well known for a series of historical novels.

Ambrose achieved fame in 1994 with his book “D-Day June 6, 1944: The Climatic Battle of World War II.” He went on to write history books, publishing more than 30.

In addition, Ambrose founded the National D-Day Museum and became a chief consultant to movies such as “Saving Private Ryan.” His book, “Band of Brothers,” was turned into a cable miniseries, and he authored a television documentary about former President Eisenhower.

But Ambrose weathered his share of hardships. Earlier this year Ambrose was accused of plagiarizing passages in a number of books. The author said he was unclear on what constituted plagiarism.

“I always thought plagiarism meant using other people’s words and ideas, pretending they were your own and profiting from it. I do not do that, have never done that and never will,” he wrote in a Milwaukee Journal Sentinel editorial.

Ambrose said his career was influenced by former UW history professor William B. Hesseltin, who told his students they would be contributing to the world’s knowledge.

“The words caught up with me. I had never imagined I could do such a thing as contribute to the world’s knowledge. Forty-five years later, the words continue to resonate with me. It changed my life,” Ambrose wrote on his website.

Ambrose was born in Whitewater, Wis., in 1936. He is survived by his wife Moira and his children, Hugh, Andy, Barry, Grace and Stephenie.

— The Milwaukee Journal Sentinel contributed to this article.