This single issue story written by Garth Ennis and penciled by Glenn Fabry introduced Kev Hawkins, a Special Air Services corporal turned unwilling assassin (due to a pesky affair when a tiger ate a cabinet minister under his protection). In the story, he is called in by the British government to remove the Authority. Supplied with an alien-created gun and ammunition, Kev manages to do this rather easily. And that's when the fun starts.
The Authority: More Kev (2004)
Ennis and Fabry re-teamed for this four-issue miniseries in which transdimensional aliens called the Rakulai threaten Earth in their search for their #1 archcriminal, Slippery B'eeef the Galactic Thief. Years ago he flew to Earth and masqueraded as a British cabinet minister, the same one that was eaten by a tiger. This, while under Kev's protection. Apollo and Midnighter must team up with their favorite homophobic SAS agent to find B'eeef's remains, since the Rakulai can regrow themselves from a single cell.
A Man Called Kev (2006-2007)
Garth Ennis and Carlos Ezquerra return for the fourth installment of Kev's adventures. No member of the Authority actually appears in this miniseries, in which Kev encounters his old tiger-sheltering friend Danny Redburn and deals with trouble from his own past.