One the highest paid and most successful coaches in collegiate football history, he led LSU to a National Championship in 2003 and Alabama to National Championships in 2009, 2011, 2012 and 2015. He received the AP Coach of the Year Award in 2003 and 2008.
He served as defensive coordinator under head coach Bill Belichick with the Cleveland Browns from 1991 to 1994.
He briefly served as an NFL head coach for the Miami Dolphins from 2005 to 2006, but then returned to college.
He married Terry Constable in 1971 and he has a son named Nicholas and a daughter named Kristen.