The country music icon Merle Haggard died today. TMZ reports that Haggard passed away after a bout with double pneumonia. Today was his 79th birthday.

Haggard was born in Bakersfield, California, where his parents had emigrated from Oklahoma, and he grew up in a boxcar that his parents converted into a house. He had a rough upbringing, spending time in various juvenile detention centers for things like robbery and assault. Backstage at a concert, Lefty Frizzell heard Haggard singing along, and he promptly put Haggard onstage, and the response he got led Haggard to pursue a music career. But while he was starting out, playing bars and clubs, he was still having trouble with the law, and he was famously in the audience at a 1958 Johnny Cash concert at San Quentin Prison.

Upon his release from prison, Haggard started recording, and his early records, along with those of his peer Buck Owens, helped develop country music’s Bakersfield Sound, which relied on a deep and heavy Fender Telecaster twang. He scored his first hit with his version of Wynn Stewart’s “Sing A Sad Song” in 1962. And in the years that followed, he cultivated an image as a dark-hearted, hard-boiled rebel with hits like 1966’s “I’m A Lonesome Fugitive.”

Haggard hit the zeitgeist hard with his 1969’s “Okie From Muskogee” and 1970’s “The Fighting Side Of Me,” conservative anthems that took on the hippies and anti-war protesters of the moment. In the decades since, Haggard has gone back and forth on whether he was serious when he wrote those songs. But either way, those songs made Haggard a hero to many, many Americans and a villain to plenty more. In 1972, California governor Ronald Reagan issued Haggard a full pardon for all the crimes that had landed him in prison in the first place. It probably wouldn’t be out of line to think of him as the Toby Keith of his era.

But Haggard was also an iconic, economical songwriter, the only man who could’ve been capable of a two-minute nugget of greatness like “Mama Tried.” Artists like Gram Parsons and the Grateful Dead, people who might’ve been Haggard’s enemies along the ideological divide, regularly covered his songs.

Haggard continued to make hits through the ’70s and early ’80s, and he stayed on the country music old-timers’ circuit for years after. Around 2000, he enjoyed a critical comeback, reemerging as a weathered roots-music badass who smoked enormous amounts of weed and spent a lot of time touring and recording with Willie Nelson. (The two released a collaborative album, Django And Jimmie, just last year.) Haggard’s health had been suffering lately, and he’d canceled a number of tour dates for this year. But he was a tough bastard, and his death still registers as a sad shock.

Below, watch some videos of Haggard at work: