Charlie Caligula started out his crime career as Little Boots Calzone, the Boy-King of Organized Crime in Rome. He came into conflict with the Roman hero the Legionary several times, before the Legionary became lax and allowed Caligula to take over the town. When the Legionary is murdered, he is murdered in a manner similar to Caesar's death in the Sheakspeare play, to cast suspicion onto Caligula and a possible Club of Villains.
When the actual Club of Villains is formed, Caligula and his centurion themed goons are drafted. The goons help take down Nightwing with Scorpiana. At the Gotham docks, Caligula and King Kraken are knocked out by Batman, now in his Zur-En-Arrh persona when he finds them at the Martus Parcking and Freight company- Martus being another name for the Roman God Mars.
Batman tortures Caligula with a baseball bat in the theater where young Bruce Wayne saw the film the Mask of Zorro with his parents before they died. Caligula isn't seen after this, but it can be assumed he isn't killed.