The character first appeared in Superman's Pal Jimmy Olsen #139 (July 1971) and was created by Jack Kirby.

Mannheim and his minions kidnap Guardian, Goody Rickels, and the Newsboy Legion and has them eat a meal laced with pyro-granulate.

Guardian forces Mannheim into giving up the antidote for the pyro-granulate enabling him to save himself, Jimmy Olsen, and Goody Rickels as well as the Newsboy Legion.

While Superman was dealing with a storm, Mannheim called a meeting with the Intergang council of war where they need to find a way to discredit Clark Kent, Lois Lane, and Cat Grant before Morgan Edge's trial.

Mannheim later abducts Kite Man, Lamelle, Rawson, Sewer King, and Squid in order to get them to join Intergang.

As of Week 48, Mannheim has captured Batwoman and has her bound and gagged to a sacrificial altar, stabbing her through the heart shortly thereafter.

When Montoya arrives and rescues her lover, Batwoman rips Mannheim's knife out of her own chest and impales him in the back, seemingly fatally.