Mark Shaw was a public defender, unhappy about how easily criminals manipulated the system and got off without punishment. Shaw’s uncle Desmond introduced him to an ancient sect of crime fighters called the Manhunters. Shaw contacted the Grand Master, the sect’s leader, through a magical lion medallion. Shortly, he assumed the Manhunter name and costume from a previous Manhunter.
It should be noted that the Manhunter sect was composed of androids, created billions of years before by the Guardians of Oa to police the galaxy. For millennia, they served the Guardians well. The Manhunters became obsessed with the act of “hunting” criminals. Their code, “No Man Escapes the Manhunters“, became more important to them than seeing justice done. Eventually, the androids rebelled against the Guardians, but were swiftly defeated by their creators. Those that survived went into hiding.
The latter-day Manhunters attempted to disgrace the Guardians with Mark Shaw at their side. They were opposed by the JLA, especially by League member Green Lantern. Shaw realized that he had been duped by the Manhunters and turned on them, killing the Grand Master, who was revealed to be a robot. Mark Shaw quickly returned as a new hero called the Privateer, but it was soon revealed that he was also working as a villain called the Star-Tsar, in league with the Key. The Red Tornado discovered this deception and Shaw went to prison.
While in the midst of serving his sentence, Shaw was offered the chance to accompany the Suicide Squad on a mission as the Privateer, and was released when the mission was completed.
In the wake of the Millennium crisis, he donned a new costume to distance himself from the Manhunter cult, and had his own adventures. Shaw now hunted costumed criminals for the bounty. He kept insisting that he was just operating for the money, but he kept finding himself doing the right thing and this is where the comic series begins.
During this series, Shaw and his family are threatened by two shape-shifters named Dumas. Shaw killed the first Dumas and his battle with the second led him to give up the Manhunter identity at the end of his series.
It was later revealed that Mark Shaw was actually himself Dumas and much of his history was actually the result of mental programming by the US Government!