In 1917, Keaton teamed up with Roscoe “Fatty” Arbuckle to launch his film career, creating short “two-reeler” comedies for a New York studio. His ingenuity as actor and director led to Keaton starting his own studio, where he made enduring classics such as The General, Steamboat Bill Jr., Sherlock Jr. and The Navigator, until in 1928 Hollywood’s biggest studio MGM persuaded him to sign a contract. This marked the end of his glory days. Faced with loss of creative control, Keaton developed a crippling drinking habit that led to collapse, hospitalisation and a hasty, ill-advised marriage to his nurse. In later, more sober years, he made appearances on television shows like The Twilight Zone and Candid Camera, performed in a French circus and starred in the short 1965 film (titled simply Film) that was Samuel Beckett’s only foray into screenwriting. In 1959, his stature was recognised with an honorary Oscar.

Curtis leaves nothing out, offering the delectable minutiae of details such as Keaton’s cherished recipe for the perfect pie-in-the-face pie (the secret is a double-baked crust, blackberries and whipped cream). Curtis invites the reader to imagine the man behind “The Great Stone Face,” emphasizing that, although Keaton was “deadly serious” about comedy (a seriousness made all the more deadly by the fact that several of the stunts he performed nearly killed him), it was not rare to see him crack a smile at one of his famous bridge parties, or when an impromptu game of baseball broke out on set.

Unlike past biographers such as Rudi Blesh, Curtis avoids the traps of reverence and romanticism. The story he tells is a remarkable one, rich with pathos, despair, triumph – but like Keaton’s Great Stone Face, he leaves those emotions for the reader to find. They are never projected on to events.

Curtis thus pays fitting tribute to Keaton’s performances, “unsmiling but certainly not without expression or feeling”, as he puts it.

“There were those who would fail to see humanity in him, who preferred the emoting that Chaplin brought fully featured to his pictures, but for audiences that considered the viewing experience a collaborative effort, he instinctively invited them into the action, and what they saw in return was a reflected humanity, a bit of themselves in what was superficially regarded as a blank pan.”

Buster Keaton: A Filmmaker’s Life is published by Knopf at £29.99. To order your copy call 0844 871 1514 or visit the Telegraph Bookshop. Renée Branum’s new novel Defenestrate is published by Jonathan Cape at £14.99.