Our tales begins in Europe during WWII, in the not at all fictional nation of Swisslakia:
So the Boy King and his Giant settled down in Central Park (!) while the U.S. gave a home to his vagabond people. And for 10 issues, Boy King and his (never named) Giant fought crooks and Nazis:
Boy King's stories included Nazi's taking over the Giant and using him to smash U.S. defenses, the Giant fighting giant Nazi robot dinosaurs, the Boy King smashing up saboteurs and fifth columnists without the Giant...Eventually, David got a sidekick, Muggsy, who turned out to be his "long-lost" identical twin brother, because comic books.
Like most heroes of the era, Boy King (and his Giant) quickly faded away after the war. But someone could revive them, right? Please?!?! Because who the heck doesn't want to read the tales of a Nostradamus-created giant metal man and his teenage royal master who go around kicking ass?!?!
Panels from Clue Comics #1-2 (1943)