Butkus, a middle linebacker for the Chicago Bears whose speed and ferocity set the standards for the position in the modern era, died Thursday, the team announced. He was 80.

According to a statement released by the team, Butkus’ family confirmed that he died in his sleep at his home in Malibu, California.

Butkus was a first-team All-Pro five times and made the Pro Bowl in eight of his nine seasons before a knee injury forced him to retire at 31. He was the quintessential Monster of the Midway and was elected to the Pro Football Hall of Fame in 1979, his first year of eligibility. He is still considered one of the greatest defensive players in league history.

“Dick Butkus was a fierce and passionate competitor who helped define the linebacker position as one of the NFL’s all-time greats. Dick’s intuition, toughness and athleticism made him the model linebacker whose name will forever be linked to the position and the Chicago Bears,” NFL Commissioner Roger Goodell said in a statement. “We also remember Dick as a long-time advocate for former players, and players at all levels of the game.”

A moment of silence honoring Butkus was held before the Bears played at the Washington Commanders on Thursday night.

Trading on his image as the toughest guy in the room, Butkus enjoyed a long second career as a sports broadcaster, an actor in movies and TV series, and a sought-after pitchman for products ranging from antifreeze to beer. Whether the script called for comedy or drama, Butkus usually resorted to playing himself, often with his gruff exterior masking a softer side.

“I wouldn’t ever go out to hurt anybody deliberately,” Butkus replied tongue-in-cheek when asked about his on-field reputation. “Unless it was, you know, important … like a league game or something.”

Butkus was the rare pro athlete who played his entire career close to home. He was a star linebacker, fullback and kicker at Chicago Vocational High who went on to play at the University of Illinois. Born on Dec. 9, 1942 as the youngest of eight children, he grew up on the city’s South Side as a fan of the Chicago Cardinals, the Bears’ crosstown rivals.

But after being drafted in the first round in 1965 by both the Bears and Denver Broncos (at the time, a member of the now-defunct American Football League), Butkus chose to remain in Chicago and play for NFL founder and coach George Halas. The Bears also added future Hall of Fame running back Gale Sayers to the roster that year with another first-round pick.

“He was Chicago’s son,” Bears chairman George McCaskey, Halas’ grandson, said in a statement. “He exuded what our great city is about and, not coincidentally, what George Halas looked for in a player: toughness, smarts, instincts, passion and leadership. He refused to accept anything less than the best from himself, or from his teammates.”

Butkus inherited the middle linebacker job from Bill George, a Hall of Famer credited with popularizing the position in the NFL. In 1954, George abandoned his three-point stance in the middle of the defensive line and started each play several paces removed, a vantage point that allowed him to watch plays unfold and then race to the ball.

Butkus, however, brought speed, agility and a scorched-Earth attitude to the job that his predecessors only imagined. He intercepted five passes, recovered six fumbles and was unofficially credited with forcing six more in his rookie year, topping it off with the first of eight straight Pro Bowl appearances. But his reputation as a disruptor extended well past the ability to take away the football.

Butkus would hit runners high, wrap them up and drive them to the ground like a rag doll. Playboy magazine once described him as “the meanest, angriest, toughest, dirtiest” player in the NFL and an “animal, a savage, subhuman.” Descriptions like that never sat well with Butkus. But they were also hard to argue.

Several opponents claimed Butkus poked them in the face or bit them in pileups, and he acknowledged that during warmups, “I would manufacture things to make me mad.” When the Detroit Lions unveiled an I-formation against the Bears at old Tigers Stadium, Butkus knocked every member of the “I” — the center, quarterback, fullback and halfback — out of the game.

And he didn’t always stop there. Several times Butkus crashed into ball carriers well past the sidelines. More than once he pursued them onto running tracks surrounding the field and even into the stands.

“Just to hit people wasn’t good enough,” teammate Ed O’Bradovich said. “He loved to crush people.”

Despite those efforts, the Bears lost plenty more games during his tenure than they won, going 48-74-4. Dealing with tendon problems that began in high school, Butkus suffered a serious injury to his right knee during the 1970 season and had preventive surgery before the next one. He considered a second operation after being sidelined nine games into the 1973 season.

When a surgeon asked him “how a man in your shape can play football, or why you would even want to,” Butkus announced his retirement in May 1974.

Soon after, Butkus sued the Bears for $1.6 million, contending he was provided inadequate medical care and owed the four years of salary remaining on his contract. The lawsuit was settled for $600,000, but Butkus and Halas didn’t speak for five years.

Butkus, like Sayers, never reached the postseason. The Bears won the 1963 championship and by the time they made the playoffs again in 1977, Butkus and Sayers were long gone.

The Bears climbed back to the top in the 1985 season with their lone Super Bowl championship. But they have been back to the title game only one time since. Butkus couldn’t understand why.

“There’s no reason why we can’t or shouldn’t be in the run all the time,” he said at the Bears’ 100th anniversary celebration in June 2019. “I know you’ve got those draft choices or whatever when you finish first all the time. How can you explain New England being up there all these years. That’s not right. The Bears should be the ones.”

After leaving football, Butkus became an instant celebrity. He appeared in “Brian’s Song” in 1971 and a dozen feature films over the next 15 years, as well as the sitcoms “My Two Dads” and “Hang Time.” He also returned to the Bears as a radio analyst in 1985, and replaced Jimmy “The Greek” Snyder on CBS’ “The NFL Today” pregame show in 1988.

Through the Butkus Foundation, he helped establish a program at a Southern California hospital to encourage early screenings to detect heart disease. He promoted a campaign to encourage high school athletes to train and eat well and avoid performance-enhancing drugs.

The foundation oversees the Butkus Award, established in 1985 to honor college football’s best linebacker. It was expanded in 2008 to include pros and high school players.

“Dick had a gruff manner, and maybe that kept some people from approaching him, but he actually had a soft touch,” McCaskey said.

The Pro Football Hall of Fame lowered its flags to half-staff in Butkus’ honor.

“Playing in an era when middle linebacker became one of the game’s glamour positions — and several of Dick’s contemporaries also would end up in the Pro Football Hall of Fame — his name most often was cited first as the epitome of what it took to excel at the highest level,” Hall of Fame President Jim Porter said in a statement.

Butkus is survived by his wife, Helen, and children Ricky, Matt and Nikki. Nephew Luke Butkus has coached in college and the NFL, including time with the Bears.