Comedian Buster Keaton's first self-made feature is essentially three two-reel comedies, one set in the Stone Age, one in Roman times and one in the Jazz Age, edited together to ape D. W. Griffith's time-jumping INTOLERANCE. Keaton deliberately fashioned his first feature this way so that, if the film bombed in previews, he could quickly re-edit it into three short films.
He shouldn't have worried so much. Although it is not one of his best constructed films, it is a pleasant and amusing comedy with great gags appearing in all three stories, which trace the history of romantic love through the ages. Keaton would go on to make some of the greatest silent comedies of the era, but THE THREE AGES acts as a link between his wild, freewheeling short subjects (represented by the Stone Age and Roman Age sections) and the realism he would strive for in his subsequent films (the jazz age sections). - JBBuster Keaton The Age of Comedy