Former Southeastern Conference commissioner Mike Slive, who led the league to unprecedented success both on and off the field and managed its growth from a regional conference to national giant during his 13-year tenure, died Wednesday after a lengthy illness.

Slive, 77, announced he was beginning treatment for a recurrence of prostate cancer shortly before he retired as SEC commissioner in July 2015. He said he had been first diagnosed with the disease in the late 1990s. He had been working as a consultant to the SEC since his retirement.

“So many people cared for Mike, worked with Mike, knew Mike that I think it’s shocking to everyone,” SEC commissioner Greg Sankey, who replaced Slive, told The Associated Press. “And that’s because of the impact he made on individuals and on conferences and on people across this country. He left a legacy certainly in this league of success and stability and growth that will always be remembered.” READ MORE>