A former Olympic archer, Clint Barton became a U.S. intelligence agent over a decade ago. Active around the world, he was present for the liberations of Kosovo and Afghanistan, as well as the fall of the Berlin Wall. He became a close friend and frequent colleague of fellow agent Nick Fury, and the two operatives were key founders of the modern intelligence agency S.H.I.E.L.D. Both rose through the ranks until Fury became the agency's director and Barton (code-named Hawkeye) became an elite agent of S.H.I.E.L.D.'s black ops division, often partnered with ex-KGB espionage legend Natasha Romanov (code-named Black Widow). Despite his dangerous, globe-spanning profession, Barton managed to build a more stable family life than most of his peers, residing for years with his girlfriend Laura (who recently became his wife), with whom he had three children: Callum, Lewis and baby Nicole, named after her godfather, Nick Fury. Hawkeye habitually phoned his family before every mission to say good-bye, just in case he never returned. He always returned, even after a mission which pitted him, Black Widow, and their support team against two office buildings full of extraterrestrial Chitauri sleeper agents. Most of their team died, but Hawkeye, the Widow and a handful of others survived, wiping out the Chitauri sleepers in the process.

Shortly thereafter, Hawkeye and the Widow were promoted to membership in S.H.I.E.L.D.'s new celebrity superhero team, the Ultimates, complete with newly falsified backgrounds to make them more acceptable public figures. When the Ultimates thwarted a Chitauri plot to destroy Earth, thanks in part to unwitting assistance from the monstrous Hulk, it was a wounded Hawkeye who managed to bring down the rampaging Hulk once the aliens were defeated. Hawkeye participated in many more Ultimates operations before taking part in the team's most controversial mission to date, teaming with the European Super-Soldier Initiative to strip a "rogue" state of its nuclear weapons capability. In response, a traitor within the Ultimates led a black ops team in to Hawkeye's home, slaughtering the entire Barton family. Though apparently slain alongside his family, Hawkeye's body was missing from the crime scene when the authorities arrived.