Mike Slive in 2012. (Dave Martin/AP)

Mike Slive, who guided college sports’s Southeastern Conference to unprecedented success and prosperity in 13 years as commissioner, died May 16 in Birmingham, Ala. He was 77.

The SEC announced the death but did not disclose the cause. Mr. Slive had battled prostate cancer shortly before retiring as commissioner in 2015.

Mr. Slive pushed for a college football playoff for the sport’s top teams years before others embraced it and was a steadying force during a time of enormous growth and volatility throughout college athletics.

The founding commissioner of two conferences, the Great Midwest Conference and Conference USA, Mr. Slive replaced Roy Kramer as SEC commissioner in 2002. Coming from C-USA, he helped an SEC that was beset by NCAA compliance issues. It soon became the most powerful conference in college football, winning seven straight national championships and landing television contracts with ESPN and CBS worth billions.

“Commissioner Slive was truly one of the great leaders college athletics has ever seen and an even better person,” said Nick Saban, the University of Alabama’s football coach. “He was a wonderful friend to me and someone who I respected tremendously. Mike changed the landscape of the Southeastern Conference and helped build our league into what you see today.”

Mr. Slive played a pivotal role in the creation of the College Football Playoff. He first formally proposed the idea of a four-team playoff for college football in 2008, but it was shot down by most of the other conference commissioners.

Mr. Slive presided over a period of unprecedented growth and success for the SEC. (Butch Dill/AP)

“I think there were many who were not all the way supportive, some wanted larger and some not at all,” Bob Bowlsby, commissioner of the Big 12 Conference, told the Associated Press. “Mike’s position was known and not everybody agreed with it. But he was statesman.”

Finally, after two SEC teams, Louisiana State and Alabama, played in the Bowl Championship Series title game after the 2011 season, the rest of college football’s power brokers came around and constructed the current postseason system.

The SEC’s success was not limited to football under Mr. Slive. Overall, the conference won 81 national championships in 17 sports during his tenure.

During tumultuous conference realignment across the nation, the SEC expanded to 14 schools from 12 with the additions of the University of Missouri and Texas A&M University in 2012. Mr. Slive was the catalyst behind the creation of the SEC Network, which launched in 2014.

He also played a major part in ushering in a new governance model for the NCAA in which the SEC and the other four most powerful and wealthy conferences were given autonomy to create and pass legislation.

Michael Lawrence Slive was born in Utica, N.Y., on July 26, 1940. He worked in his father’s butcher shop as a meat cutter.

He received a bachelor’s degree from Dartmouth College in 1962 and graduated from the University of Virginia School of Law in 1965. He received a master of laws degree from Georgetown University Law Center in 1966.

Mr. Slive founded a law firm that assisted schools with NCAA compliance issues before starting a long career in college sports. Upon his retirement, he founded the Mike Slive Foundation for Prostate Cancer Research.

Survivors include his wife of 49 years, Liz Slive; a daughter, Anna Slive Harwood; and one granddaughter.