[3][4] Millar has written numerous creator-owned series which have been published under the unified Millarworld label, including Wanted with J. G. Jones, Kick-Ass with John Romita, Jr., Nemesis with Steve McNiven, Superior and Supercrooks with Leinil Francis Yu, The Secret Service with Dave Gibbons and Jupiter's Legacy with Frank Quitely.

[9] The first comics that Millar read were the seminal The Amazing Spider-Man #121, which featured the death of Gwen Stacy, and a Superman book purchased by Bobby that day.

[8] Millar's interest in the medium was further cemented with the black-and-white reprints of other comics that his brothers purchased for him,[7] which he enjoyed so much that he drew a spider web across his face with an indelible marker that his parents were unable to scrub off in time for his First Communion photo a week later.

[8] In the mid-late 1970s, Millar frequently appeared as a guest on the long-running Scottish kids TV programme Glen Michael's Cartoon Cavalcade, which he was a regular fan of at the time.

On one occasion, he was invited onto the show to talk about the history of comics and, in a 2010 interview with the Scottish newspaper Daily Record, Millar has stated that Glen Michael's TV programme was where he first discovered superheroes.

Illustrated by Daniel Vallely, Morrison's former bandmate in The Mixers and, earlier, The Fauves,[14] Saviour provided a mix of religious themes, satire and superhero action that quickly brought Millar to the attention of the wider British comics industry and resulted in several script commissions for the long-running anthology 2000 AD and its sister title Crisis.

[15] Although Millar's further work on Swamp Thing brought some critical acclaim to the ailing title, the book's sales were still low enough to warrant cancellation by the publisher.

Millar, a self-proclaimed Superman fan,[13][33] stayed on the title for two years and received two Eisner Award nominations[34] while penning one-off stories featuring the version of the character from the mainline DC Universe.

[44] As a result, the creators repeatedly requested a "Suggested for Mature Readers" label for the series but the idea was vetoed by then-Publisher of DC Comics Paul Levitz.

[51] The line, designed to simplify and streamline the company's long-running fictional continuity for mainstream audiences, was met with instant critical and commercial success[52] and, soon after the launch of Ultimate X-Men, Millar announced that he had signed a two-year contract for a staff writing position at Marvel.

In November 2000, Millar and Quitely announced their plans to leave The Authority after the third story arc,[53][41] which was supposed to run in issues #22–25 (cover-dated March–June 2001) if the series was to maintain a monthly schedule.

[1] Actor Aaron Taylor-Johnson, who portrayed the character Quicksilver in the 2015 sequel film Avengers: Age of Ultron, stated that it also drew inspiration from the Ultimate comics.

In 2003, Millar and artist Terry Dodson launched Trouble at Marvel's newly-revived Epic imprint,[74][75] a series meant to re-popularize romance comics that ended up both a sales and critical failure.

[85] During this period, Millar was assigned to write a trilogy of mini-series that would introduce Galactus to the Ultimate Universe but he left the project due to other commitments at Marvel[86] and health issues.

[87] In 2006, after renewing his exclusive contract with Marvel for two more years,[66] Millar launched the most well-known and best-selling work of his career, the 7-issue mini-series Civil War with artist Steve McNiven that acted as the centrepiece of the company-wide crossover storyline of the same name.

[94] In 2008, Millar returned to the Wolverine ongoing series for an extended dystopian storyline "Old Man Logan", illustrated by his Civil War collaborator Steve McNiven.

[3][4] Also in 2008, Millar reteamed with The Ultimates co-creator Bryan Hitch for a run on the mainline Fantastic Four series[97][98] and launched the mini-series Marvel 1985 with artist Tommy Lee Edwards.

[112][113][114] Another unreleased project was King and Country, a political drama involving the British royal family repurposed from a TV series pitch Millar created in 2005.

[94] In 2008, the Millarworld line expanded with two new releases, War Heroes at Image, and Kick-Ass, published under Marvel's Icon imprint and adapted into a feature film two years later.

Millar began work at 9 am, plotting a 20-page Superior story, followed by more than 60 comic book creators—including Sean Phillips, Dave Gibbons, Frank Quitely, John Romita Jr., Jock,[120] Doug Braithwaite, Ian Churchill, Olivier Coipel, Duncan Fegredo, Simon Furman, David Lafuente, John McCrea, Liam Sharp[121]—who appeared on stage throughout the day to create a panel each.

The black-and-white book was completed in 11 hours, 19 minutes and 38 seconds, then published through Marvel's Icon imprint on 23 November 2011, with all royalties being donated to Yorkhill Children's Foundation.

[134] That same year, Joe Roth and Jeff Kirschenbaum signed on to produce Empress with XXX: Return of Xander Cage writer F. Scott Frazier set to pen the screenplay.

[147][148] In his writing, Millar has incorporated the themes of domestic abuse (The Ultimates),[149] teenage pregnancy (Trouble),[150] child molestation (The Unfunnies)[151] and rape,[27][152] the latter sometimes for comedic effect.

[15][52] Morrison was seen as the mentor figure in their relationship,[29][166][167] as evidenced by a humorous strip created by Garth Ennis and Dave Gibbons for an anniversary issue of 2000 AD in which Millar appeared in the form of a small droid repeating a single phrase, "me and Gwant".

[168] The pair was also parodied in an issue of Simpsons Comics written by Gail Simone, shown fighting over whose then-ongoing X-Men series—Millar's Ultimate or Morrison's New—is more important.

[170] When asked about the state of their relationship in a 2011 interview, Morrison responded thus, "I wish him well but, no, there is no good feeling between myself and Mark Millar for many reasons most of which are he destroyed my faith in human fucking nature.

[6] The six-metre-high archway, created as part of the efforts to reinvigorate the canal, was inspired by Millar's work, depicting a superhero named Captain Coatbridge and two superheroines.

[172] In June 2013, Millar was appointed a Member of the Most Excellent Order of the British Empire (MBE) for services to film and literature on the Queen's Honours Birthday list.

Other comic book creators he names as influences include Dave Sim,[179] Grant Morrison, Peter Milligan, Warren Ellis, and Garth Ennis.

[184][66][185] Speaking about his political views, Millar has described himself thus, "I regard myself as traditionally left of centre and progressive, a Eurosceptic in the Bennite mould, and the policies espoused by the coalition formed under the Yes umbrella are the closest to my own particular ideology.