Dick Butkus, one of the greatest linebackers in NFL history, has died, the Chicago Bears announced on Thursday night. He was 80 years old.

According to the Bears, Butkus passed away in his sleep at his Malibu, Calif. home during the overnight hours of Thursday morning.

A star at Illinois, where he was a 2-time All-American and former Big Ten MVP, the Chicago native was chosen by his hometown team with the 3rd overall selection in the 1965 NFL Draft and was a 2nd-round pick in the AFL Draft that same year. He played 9 seasons with the Bears and was a 5-time 1st-team All Pro and 8-time Pro Bowl selection. He was the NFL Defensive Player of the Year in back-to-back season (1969 and 1970).

Butkus was also named to the NFL’s All-Decade Teams in both the 1960s and 1970s, and was later part of the league’s all-time teams for its 75th and 100th-anniversary.

After his football career, Butkus pursued a career in broadcasting and entertainment. He was eventually named to the Pro Football and College Football Hall of Fames in 1979 and 1983, respectively. His college number (50) was retired by Illinois, as well as his professional number (51).