Former undisputed middleweight boxing champion passes away at the age of 66.

Kay Guarrera Hagler, the wife of legendary boxer Marvin Hagler, posted the news on her husband’s Facebook fan page, but she did not give the cause of death.

“I am sorry to make a very sad announcement. Today unfortunately my beloved husband Marvelous Marvin passed away unexpectedly at his home here in New Hampshire. Our family requests that you respect our privacy during this difficult time. With love, Kay G. Hagler,” she wrote.

Hagler was born on May 23, 1954 in Newark, N.J. and had many notorious fights and victories during his career. He had wins over other legends, such as Thomas Hearns and Roberto Duran.

Out of 67 bouts he lost three times, won 62 fights and had two draws with 52 of those wins won by a knockout, which gave him a 77.61% KO rate.

He defended the undisputed crown 12 consecutive times until losing to Ray Leonard.

His last fight was on April 6, 1987 against his long time rival “Sugar” Ray Leonard. He ended up losing that fight, which is one of the most disputed results in boxing history. That loss and decision upset him so much that he hung up the gloves and retired.

After retiring, Hagler moved to Italy to pursue a an acting career. He stared in action roles in Italian film “Indio” and “Indio 2.” He also did work for the “Fight Night: Round 3” video game.

His legendary run allowed him to be one of the “Four Kings” along side Roberto Duran, Ray Leonard and Thomas Hearns.

He didn’t let the game of boxing change him and the people around him. He kept his original trainers and managers and never tried to get more famous by jumping to more famous promoters. Although it may have cost him potential bigger fights and more fame, he stayed true to himself.

He will be missed but never forgotten, thanks to the legacy he left behind.