The Kingmaker has been active for at least 15 years now, as he has helped Julian Keller's parents in gaining a fortune and becoming influential businessmen. He has also become associated with Doctor Octopus at some time. He is a man who uses great influence and weath to get his client whatever they want.
The most public encounter he has been involved with was between him and a group of young students known as the Hellions, from the Xavier Student. They all called him up asking for his services, following the disowning of Julian Keller, aka Hellion.
He granted Santo Vaccaro, aka Rockslide his wish to be a wrestler first, proving to the rest of the kids that he could do things for them. He then denied a wish from Brian Cruz aka Tag, and finally granted all the other wishes. Cessily Kincaid, aka Mercury, was reunited with her anti-mutant parents, though they were mind controlled, Sooraya Qadir, aka Dust, was able to see her mother again, Kevin Ford aka Wither, was cured of his mutant powers, Julian was granted fame, and Brian was given the task of managing them all, as was his request.
Kingmaker then asked them to get a case for him, as Doctor Octopus needed it, and they had to do it for him or lose their wishes, which none of them wanted to do. They faced off against Diamondback and Paladin, but managed to retrieve the case. After giving it to him, the Hellions decided to take it back rather than be criminals. After a long confrontation with them, he was defeated, but escaped.
Emma Frost then warned him to stay away from the kids, or face the X-Men's wrath, as well as her wrath. His current whereabouts are unknown, but he is undoubtably still doing what he does.