Midnighter, alongside his future husband Apollo, was part of a top secret StormWatch team created by the first Weatherman, Henry Bendix. Nobody but Bendix himself knew of the team's existence. Bendix built them as superhuman and, when they donned their costumes and spoke their codenames, their previous identities ceased to exist. However, this secret team was all but destroyed during their first mission, Apollo and Midnighter being the only survivors. They went rogue and spent the next five years undercover fighting for a finer world in the alleyways of America. One mission took them to Britain, where they thwarted Bendix's attempts at experimenting on children to create superhumans, in the process developing links with MI5. They remained unknown to Stormwatch until Christine Trelane found the files about their team after Bendix's fall.
Jackson King, formerly Battalion, now the new Weatherman, ordered them found, not being sure whether they were heroes or villains. Midnighter and Apollo were after weapons made in the "Nevada Garden", a relic of the first Engineer. He ordered Fahrenheit and Hellstrike to tag them with fetishes so they could be transported into SkyWatch. Midnighter and Apollo first attacked the Stormwatch team, believing them under Bendix's orders. However, they ceased the attack once they were told Bendix was dead. With King's help, they violently retrieved the Garden from the U.S. Army, and King granted them what they asked for: new lives away from Stormwatch. After Stormwatch was destroyed, Jenny Sparks convinced both Midnighter and Apollo to come out of retirement and join her new group, The Authority. A formidable fighter with a sardonic attitude, Midnighter epitomized the new team's commitment to fighting for a finer world, including against vested interests and world governments. He was the architect of the team's first significant victory, the defeat of autocratic dictator Kaizen Gamorra, which he achieved by dropping the 50-mile-long Carrier on to Gamorra's island base. Midnighter was the only Authority member to evade capture when the US government had the team attacked and replaced with manipulable substitutes. Presumed dead, Midnighter had in fact escaped the Carrier with baby Jenny Quantum. He returned to overthrow the puppet team and rescue Apollo from imprisonment and abuse at the hands of their replacements. Shortly thereafter Midnighter and Apollo were married and adopted Jenny.
Midnighter took a central role during the Authority's brief over the United States. A visitation, apparently from a future Apollo, convinced Midnighter that he was on the path to becoming a malign dictator. To avoid this fate Midnighter quit the team, precipitating its break-up, and returned to life fighting solo on the streets. Raised alone by Apollo, Jenny exploited her powers to age herself to young adulthood and reformed the Authority. Having convinced Midnighter to rejoin the team Jenny discovered he was being manipulated by a dimension-hopping Henry Bendix, hitherto assumed dead. Midnighter fought for Bendix before the Engineer was able to break the mind-control; Midnighter then killed Bendix by ripping out his spine.
Circumstances have twice forced Midnighter, very much against his will, to team up with Kev Hawkins, a homophobic former-SAS soldier and eponymous protagonist of the Authority. A relationship made worse by the fact that on their first meeting, Kev killed him, Apollo and the rest of the Authority, though the Carrier resurrected them. On their last meeting they took down MI5's Royal Oak project, an attempt at replicating Bendix's experiments.
(From DC Database)