Apparently, Mel Brooks had run out of movie genres that warranted spoofing in their own movie, so he threw together this occasionally successful hodge-podge of historical epics. This movie probably would have worked better if Brooks had found a few more historical periods to include.
As it is, the Roman segment, with Brooks as a “standup philosopher” named Comicus in the court of Emperor Nero (Dom DeLuise), drags on and on, with too few jokes to justify its length. The final scene of this part, with Comicus waiting tables at the Last Supper would have worked better as a sketch on its own without all of the build-up.
The French Revolution segment, with Brooks as both the lecherous King Louis XVI and his unfortunate double, Jacques the royal “piss-boy,” is better paced and contains most of the film’s best material. Harvey Korman, however, largely repeats his role from Blazing Saddles as the pompous schemer whose name everyone mispronounces.
Other brief interludes, such as the caveman sequence with Sid Caesar, are a mixed bag. The caveman stuff is a lot of slapstick, most of it quite funny. The “Spanish Inquisition” musical number has its moments, too, but just goes on far too long. The Ten Commandments spoof builds up to one punch line and then it’s over.
All told, History of the World seems like Brooks was running out of creative gas after a long, successful run during the seventies. Unfortunately, his work since has demonstrated that he hasn’t recovered his comedic mojo.