Crime and criminality became the popular theme of these films. In The Naked Truth, Dennis Price blackmails (among others) Peter Sellers and Terry-Thomas. Sellers reappears as an old lag in Two-Way Stretch and a rogue couturier in The Wrong Arm of the Law, and Terry-Thomas plays the philandering husband only too glad to have his wife kidnapped — he refuses to pay the ransom and she joins forces with her kidnappers to punish him — in Too Many Crooks. The black-and-white Carry On films, with what at the time were considered second-division comics, follow on naturally from these entertainments, but as the permissive society takes hold, standards change and reticence disappears, they decline to an ignominious end.

It is not quite true, however, that British comedy films stop being funny once filmed in colour. Perhaps the most magnificent moment in any of the films — in Carry On Don't Lose Your Head, about the French Revolution, and worth repeatedly pausing and rewinding the DVD for — is Joan Sims's enunciation of the phrase "my brother, the Count", in which she almost succeeds in making the aristocratic title rhyme with "hunt". But there can be no doubt which is the most magnificent film in the series, Carry On Up the Khyber, filmed at Pinewood and in Snowdonia (impersonating the North-West Frontier) in the spring of 1968 in the most glorious colour.

It is the definitive Carry On film. Most of the great stars are in it; and the intensity of the gags is so relentless that one is forced to admit that great music-hall comedy requires little short of genius. Sid James and Joan Sims play Sir Sidney and Lady Ruff-Diamond, and Peter Butterworth is the local missionary, Brother Belcher. Charles Hawtrey is the most unmilitary of soldiers, Private Widdle, of the 3rd Foot and Mouth, and a comrade is Private Ginger Hale. Kenneth Williams plays the local nabob, who is of course called the Khasi of Kalibar, and Bernard Bresslaw is his sidekick Bungdit Din. It is a deeply patriotic film, for once the 3rd Foot and Mouth have routed the revolting natives by the simple expedient of standing in a line before them and raising their kilts, the film ends with a shot of a fluttering Union Flag bearing the motto "I'm Backing Britain". I hope, for philosophical reasons, that the film will be shown on television in Scotland on the eve of the referendum on independence.