Amol Rajan: Why we're all still living in Walmington-on-Sea

When David Croft, who died this week aged 89, received a script about "the trials and tribulations of the Home Guard" from an actor working for him called Jimmy Perry, he was instantly impressed. The working title was Fighting Tigers, and Croft and Perry would go on to make it possibly the finest situation comedy in British television history. Except the BBC changed its name to Dad's Army.

What's in a name? Only the possibility of comedy. The difference between Fighting Tigers and Dad's Army is the latter contains a contradiction, because grey-beards tend not to make the best gunmen. Tigers fight; dads play golf. The whole joke in Dad's Army was the improbability of the little platoon of elderly men from Walmington-on-Sea fighting Nazi invaders.

Croft said his policy was to avoid funny lines; if the characters are funny enough, the audience will laugh whatever they say. The characters were therefore sharply drawn and delineated, from Captain Mainwaring, the leader with an inferiority complex, to Corporal "They don't like it up 'em" Jones and Private "Stupid Boy" Pike.

What elevated Dad's Army from popular sitcom to television gold was that it got closer than any other programme, before or since, to capturing our national character. This was easier when Britain was a less culturally diverse place, and made easier still by the invocation of our alleged finest hour.

The spirit of a people, usually so elusive, was here captured in half-hour bulletins. There was the nostalgia for days of greatness (read: Empire), the love of hierarchy and institutions, and the inescapable fact that Britain is still the most class-ridden country under the sun. There was gleeful indulgence of underdog status. Above all, there was persistence in the face of adversity.

The character to which the British most aspire and most often fall short, but in war frequently obtain, is fortitude. The men of Walmington-on-Sea, forced together by circumstance, could find points of humour and optimism in the dog days of war; and even in their disputes and petty rivalries were bound by a common purpose, of victory for their country.

Coming from a man whose life was devoted to comedy, this perfect portrait of a people's spirit was a serious achievement. David Croft put a mirror to the nation, and found it couldn't stop laughing at the reflection.