Short answers, pulled from the story.
Mark Millar is a Scottish comic book writer born on the 24th of December 1969 in Coatbridge, Scotland. He is best known for The Ultimates, Civil War, Kick-Ass, and The Secret Service, as well as the creator-owned Millarworld label that Netflix purchased in 2017.
Captain America: Civil War (2016), based on Millar and Steve McNiven's Civil War mini-series, earned more than a billion dollars at the box office. Logan (2017) drew on Millar and McNiven's "Old Man Logan" storyline. The Avengers (2012) was described by its co-story creator Zak Penn as majorly inspired by Millar and Bryan Hitch's The Ultimates.
Netflix purchased Millarworld in August 2017 for an undisclosed sum. Millar noted it was only the third time a comic book company had been acquired by a production studio, comparing it to DC Comics being bought in 1967 and Marvel being acquired by Disney in 2009.
Millar and Morrison were close friends and frequent collaborators throughout the 1990s and early 2000s, co-writing works including Big Dave, Aztek: The Ultimate Man, The Flash, and Skrull Kill Krew. Around 2004, they ended all contact. Morrison later said of the split that Millar had "destroyed my faith in human fucking nature."
Millar was appointed a Member of the Most Excellent Order of the British Empire in June 2013, appearing on the Queen's Birthday Honours list for services to film and literature.
Civil War is a seven-issue mini-series by Millar and artist Steve McNiven published in 2006, centred on the Superhuman Registration Act dividing Marvel's heroes. It won Millar the 2007 Harvey Award for Best Single Issue for the first issue. Marvel Studios adapted it as Captain America: Civil War in 2016, earning more than a billion dollars worldwide.