PHOENIX >> Wayne Duke, who was a driving force behind the expansion of the NCAA men’s basketball tournament during his 18 years as commissioner of the Big Ten, has died. He was 88.

The Big Ten announced Duke’s death after his family notified the conference on Wednesday. He had been living in Barrington, Ill., and had been in declining health, his wife, Martha, told The Associated Press.

After serving for 11 years as assistant to Walter Byers, the first executive director of the NCAA, Duke became commissioner of the Big Eight conference in 1963 at the age of 34. He took over as Big Ten commissioner in 1971 and retired in 1989.

Duke guided the Big Ten and college sports through the first stages of great growth in revenue from television coverage of football and basketball.

“Wayne was a giant in the world of college athletics administration during times of great change,” said Big Ten Commissioner Jim Delany, who replaced Duke at the conference. “He was a champion of the student and was responsible for many of the academic, athletic and social initiatives that our students today benefit from. His mantra was ‘Performance commands respect,’ and his performance and dedication throughout his college athletics career earned him the respect of countless administrators, coaches, media and fans across the country.”

Duke served on the NCAA men’s basketball committee from 1975-81. He oversaw the expansion of the tournament from 32 to 48 teams and was in charge when the at-large berths were established and seeding began. Previously, only conference champions played in the NCAA Tournament.

Duke was on the NCAA’s basketball television negotiating committee when the association struck its first big deal with NBC to nationally televise much of the tournament. Duke also had a role in the NCAA’s first football TV contract.

In 1981, Duke was overseeing his last NCAA basketball tournament as the selection committee chairman. President Reagan was shot in Washington on the same day of the national championship game in Philadelphia. After hours of agonizing, and assurance the injuries were not life-threatening, the game was played.

“I thought we had done right,” Duke told the AP in 2003. “Somehow, during the game, it came to us that Reagan had spoken from his hospital bed and said, ‘All in all, I’d rather be in Philadelphia.’”

In 1963, Duke faced a similar situation as commissioner of the Big Eight.

The Oklahoma-Nebraska football game was supposed to be played the day after President Kennedy was assassinated in 1963.

“It was going to be Bud Wilkinson’s last game at Oklahoma,” Duke said in 2003. “We were making the decision on postponing the game when Bud, who was the chairman of President Kennedy’s Council on Physical Fitness, got hold of Bobby Kennedy, and he told us to play the game because there was such a state of turmoil in the country people needed a pickup.”

Duke was the first full-time employee of the NCAA, hired by Byers in 1952. Handbooks that Duke wrote for the basketball tournament and College World Series set foundations for those events that have stood for decades.

He was considered a groundbreaker on affirmative action and the growth of women’s sports in the 1970s.

As commissioner of the Big Ten, Duke suspended Indiana coach Bob Knight for throwing a chair across the court and Ohio State coach Woody Hayes for dismantling a sideline marker.

“If you follow the guidelines laid out and believe in them, those types of things are taken care of,” Duke said.

After retiring from the Big Ten, he went on to establish the Maui Invitational basketball tournament that still annually draws top teams to Hawaii early in the season.

Duke went into the National Collegiate Basketball Hall of Fame in 2010.

Duke was born in Burlington, Iowa, and graduated from the University of Iowa in 1950. He is survived by wife Martha Duke, son Dan, daughter Sarah, four grandchildren and four great-­grandchildren.