The Keystone Film Company is one of those film studios whose name immediately conjures up a host of associations. Founded in 1912 by Irish-Canadian Mack Sennett, Keystone was the studio where many of the legends of silent film comedy first became stars – Mabel Normand, Ford Sterling, Roscoe “Fatty” Arbuckle, Charlie Chaplin, and Ben Turpin, among many others. It was a company that defined a hugely influential style of fast-paced knockabout: the frantic Keystone cops, crazy chases with flivvers and police wagons, and, of course, the Bathing Beauties – all of these made an indelible mark on US culture at the beginning of the twentieth century. Keystone is unquestionably the most important film company in the history of American comedy.For me, though, the crucial issue is to ask why Keystone was so influential. Why this style of screen comedy, rather than any other? After all, it’s not as though the studio was the only one, or even the first, to put slapstick comedy on screen. There were other comic filmmakers prior to Keystone’s, many of whom were extremely popular (people like Augustus Carney and John Bunny, to say nothing of the French comedian Max Linder). If we really want to understand the nature of Keystone’s contribution, it seems to me, we have to adopt a perspective that looks beyond the studio gates to consider the company’s meaning in the larger cultural landscape of the time.In its broadest strokes, this is what The Fun Factory tries to do. The book is at once a studio history and an analysis of that studio’s cultural moment.