Born and raised in Chicago's South Side, he began his recording career as a teenager and initially garnered regional attention and praise for his mixtapes in the early 2010s.

[7][8][9][10][11] His fifth mixtape, Back from the Dead (2012), spawned the single "I Don't Like" (featuring Lil Reese), which became a local hit and marked his first entry on the Billboard Hot 100.

[12][9] Rolling Stone has credited Cozart with "personif[ying] Chicago drill",[13] while Stereogum referred to him as a "modern rap folk hero".

[15] He lived at the Parkway Garden Homes located in the Washington Park neighborhood on the city's South Side, a stronghold for the Black Disciples street gang of which Chief Keef is a member.

[34] In the summer of 2012, Chief Keef was the subject of a bidding war among record labels wishing to sign him, including Young Jeezy's CTE World.

[37] Featured guests on the album include rappers: 50 Cent, Wiz Khalifa, Young Jeezy, Rick Ross and his fellow Glory Boyz member Lil Reese.

Meaghan Garvey of The Fader noted this was fitting as the rapper has "always been more concerned with vibe than meaning, and production is his most efficient tool to create a mood without getting bogged down by pesky syntax.

[48] During February, Chief Keef said his former lean addiction and bad mixing contributed to the lack of quality music on his two mixtape projects Bang Pt.

[51] In March, Keef released the first official single from Bang 3 entitled "Fuck Rehab" featuring his fellow Glo Gang artist and cousin Mario "Blood Money" Hess.

[62] David Drake of Pitchfork Media said, "For his first steps into the rapper-producer territory, he shows promise—though it's tough to imagine most of these beats working outside the context of a Chief Keef album, as they are primed to frame his vocals.

[69] Elliott Pearson of The Alibi commented: "Sorry 4 the Weight is another consistent chapter in the rapper's singular Midwestern gothic repertoire, and if 'What Up' is any indication, he's made serious progress as a beat-maker too.

[77] On July 11, 2015, Marvin Carr, better known by his stage name Capo, a longtime member of Chief Keef's Glo Gang label, was shot and killed in a drive-by shooting in Chicago.

Chief Keef announced on Twitter he would be holding a free benefit concert as a tribute to Capo and encouraged concertgoers to donate to the Harris family.

[81] It faced a series of delays after Chicago mayor Rahm Emanuel's office claimed Chief Keef was "an unacceptable role model" and that his music promoted violence.

[84] Fearing the concert was a threat to public safety, Hammond mayor Thomas McDermott, Jr. had the city's police department shut down the generators powering Chief Keef's hologram.

"[84] Chicago Tribune columnist Eric Zorn criticized Emmanuel and Hammond for their decisions, claiming they infringed upon Chief Keef's First Amendment rights.

[89] Chief Keef joined a long line of rappers, including Jay-Z, Lupe Fiasco, Nicki Minaj and others, who claimed to have retired only to return to making music.

[98] In March 2020, Chief Keef earned his first major production credit on Lil Uzi Vert's second studio album, Eternal Atake, with the song "Chrome Heart Tags".

Chief Keef's cousin and fellow rapper, Fredo Santana, his uncle Alonzo Carter, and Anthony H. Dade, owned the remaining 20% of GBE.

[105][106] Prior to his death, Blood Money revealed in an interview the members of Glo Gang were Chief Keef, Tray Savage, Ballout, Capo, Tadoe, JusGlo, and himself.

[118] Another of his cousins, Mario Hess, also known as Big Glo, who performed under the stage name Blood Money, was shot and killed in Chicago's Englewood neighborhood on April 9, 2014.

[126] On September 5, 2012, Chicago Police stated Chief Keef was being investigated for a possible connection to the shooting death of fellow rapper and Englewood resident, Joseph Coleman, who performed under the stage name "Lil JoJo".

[133] Although prosecutors requested that he be jailed, Cook County judge Carl Anthony Walker allowed him to remain free, saying he had not been presented with "any credible evidence" to warrant incarceration.

[134] Chief Keef was taken into custody on January 15, 2013, after a juvenile court judge ruled that the gun range interview video constituted a probation violation.

[145] On February 4, 2014, Kim Productions filed suit against him to recover losses they allege were incurred after he failed to appear at a RapCure benefit concert in Cleveland, Ohio, in June 2013.

The New York Times writes, "Lupe Fiasco is a stern and didactic teacher, but it's arguable that Chief Keef's music is far better at ringing warning bells.

His melodic style of rapping and his characteristically slurred delivery of lyrics has been called the catalyst for the success of Chicago drill and Mumble rap, and an influence on a large number of modern artists especially such as: 21 Savage, YoungBoy Never Broke Again, Lil Uzi Vert, Playboi Carti, Lil Pump, XXXTentacion, Ski Mask the Slump God, Trippie Redd, Juice Wrld, Polo G, and Tay-K among the others, even pop artists like Doja Cat and Billie Eilish.

Additionally, Chief Keef's heavy use of adlibs, specifically the word "aye" as a large part of a song was a major influence on the Soundcloud rap subgenre and the artists that emerged from it.

[159][160] In an August 2012 interview with Baltimore radio station 92Q Jams (WERQ-FM), Lupe Fiasco stated that Chief Keef "scares" him and described him as a "hoodlum" and a representative of Chicago's "skyrocketing" murder rate.

[170][171] On May 8, 2018, Trippie Redd previewed the song "I Kill People" on Instagram, featuring Chief Keef and Tadoe, which was aimed as a diss toward 6ix9ine and Cuban Doll.