It has taken only a few decades to go from the days when smoking was ubiquitous to last week's declaration by Parliament that makes it illegal in enclosed public spaces. Thus will history see the every-present cigarette as a purely 20th-century phenomenon, looking as bewildering to future generations as the wearing of ruffs in Elizabethan England does to us today.

Nothing seems so dated now as the white sticks in the mouths of Laurence Olivier and Marilyn Monroe facing the press at the Savoy in 1956. But to onlookers then, the picture would have suggested that both were relaxed and confident; he was debonair in the way he proffered his lighter (Dunhill, probably), she liberated enough to accept.

Sean Penn in Tehran, Iran. 2005

Smoking was, from the 1920s to the 1960s, far more than just a universal addiction. Everything about it sent a social signal: from the brand (Weights for the workers, Sobranie for those wishing to cut a dash) and the location (only "fast" women smoked in the street), to the smokers' requisites. A holder, for instance, was first a mark of sophistication, then of affectation; ditto the smoking jacket, a garment sported by would-be Noel Cowards trying to exhale clipped-tone aphorisms like smoke rings in words. Even the way you held the thing made a statement. Cloth-cap wearers and school-boys smoked with lit fag hidden in a cupped hand from wind or teacher, while the anyone-for-tennis brigades held it up brazenly and never called it a fag. "Have a gasper, old chap," they'd say.

All this was reinforced by, and some of it was learned from, the movies. Up on screen there were almost heroic feats of consumption, like Humphrey Bogart's 13 cigarettes in Casablanca: or women lighting up to show their experience (or willingness to acquire it), witness Bette Davis smoking furiously and alone in Now, Voyager. The message was: if you want to be slim, sexy, sophisticated, dangerous, knowing, quizzical, raffish or racy, then have a cigarette.

Humphrey Bogart and The Maltese Falcon

Advertising sent its own smoke signals. Besides all that kindness to the throat that the posters promised, there was no end of big names to identify with. Fred Astaire, Betty Grable and Rita Hayworth smoked Chesterfields. Joan Crawford and Claudette Colbert backed Lucky Strike, While Merle Oberon and June Havoc swore by Regents. Even the Journal of the American Medical Association ran cigarette ads.

Thus, by the 1940s, there was something a bit odd about you if you didn't smoke. Despite the link with lung cancer being suggested in 1912, and largely proven by the early 1940s, no government dared act - except one. The country where smoking was banned in public buildings, buses, trains, restaurants and bars, and where the concept of passive smoking was 'conceived' was Nazi Germany, ruled by a man who put a match to civilisation, but not to a cigarette. At the end of the Second World War, two prominent anti-smoking campaigners committed suicide rather than face trail for participating in the euthanasia programme. One was executed for crimes against humanity. How strange to believe that while secondhand smoke was a crime, genocide was not.

David Randall