Ronald Searle: Illustrator and cartoonist who created the anarchic world of St Trinian's

English cartoonist and illustrator Ronald Searle at his work desk in 1956 (Getty)

It is tempting to make a casual connection between the horrors that Ronald Searle suffered as a prisoner of the Japanese during the Second World War and the black humour of his most famous cartoon creation, the gothic girls' school St Trinian's.

In both camps, casual cruelty was the order of the day. The Japanese guards bludgeoned and murdered. So too did the vicious imps of St Trinian's, though they also indulged more exotic vices, including drink and drugs and the suggestion of sexual impropriety. Their insouciant teachers were more concerned to correct their speech than stop them stabbing each other to death with dinner forks.

It's hard to imagine so violent a product being mass-marketed today, but in 1948, when the first book of cartoons, Hurrah for St Trinian's, appeared, Britain needed to exorcise its recent violent past with laughter. Searle thought he was allowed licence because, "however outrageously sick or gruesome, it was always cosily British". This holds true of his more recent work, despite the fact that he spent the last 50 years of his life in France.

For all its darkness, Searle's satire rarely appeared overly cruel, unlike that of Gerald Scarfe or Ralph Steadman, who, like many other artists, were stylistically influenced by him. Searle's name has often been lumbered with superlatives – "finest graphic draughtsman of the century", "best satirical draughtsman", and so on – which need to be reckoned seriously. He has been cited as a model by princes of humour as disparate as Groucho Marx and Matt Groening, creator of The Simpsons, a sampling that testifies not only to his comedic skills and artistry, but also to the span of his productive years.

Searle's appreciation of the dark side went back to his childhood. As a small boy, he was transfixed by a tattoo of a Chinese head pierced by a dagger on his railway-worker father's back; by the engraving of a 1736 Edinburgh lynching hanging in his parents' hall; by the slaughterhouse he visited when he worked as a butcher's boy, and by the illustrated books of surgery and mental deficiency he collected. He may even have inherited a black-humour gene. When his mother, Nellie, discovered a minor physical oddity in one of his earlobes, she remarked that it might come in useful one day if she ever had to identify his body in a morgue.

Searle wasn't just an original cartoonist; he was an original artist, and his determination to make whatever unpopular or painful sacrifice necessary to stretch his own creative boundaries was apparent throughout his life. At the same time as his St Trinian's creations began to bewitch the public, Searle produced an exhibition at the Cambridge School of Art and a book of drawings of his fellow sufferers in Changi jail, Singapore, and of the forced labour gangs on the Burma-Siam railway of 1943, where 95 per cent of prisoners perished.

Searle had sketched with tiny pencil stubs on recovered scraps of paper, risking summary execution if discovered, often concealing his work under the bedclothes of those dying of cholera. He escaped cholera himself, but suffered simultaneously from two types of malaria, beri-beri, dysentery, flesh ulcers and a wound to the back caused by a blow from a guard's pick-axe, which had penetrated to his spine. At one point, when he weighed just seven stone, his fellows left him out in the sun to die. Yet Searle survived and returned with a bounty of hoarded work to England.

The war book, Forty Drawings (1946), was not comfortably received, though it helped establish Searle's reputation as a serious artist.

The demobbed soldier grew a fashionable goatee beard and quickly began a relationship with a married woman five years his senior, Kaye Webb, who, as assistant editor of the literary magazine Lilliput, published his first (and only pre-war) St Trinian's cartoon in 1941. In 1946 she bore him twins, a boy and a girl, married him, and plunged him into London's literary social circuit.

The late Forties and Fifties saw him working a schedule that taxed even this workaholic. As well as serving the St Trinian's monster, he collaborated with the writer Geoffrey Willans on the anarchic Nigel Molesworth books, with a miscreant schoolboy as hero. He drew a series of lucrative advertisements for Lemon Hart rum, illustrated many books and performed the schizophrenic role of political cartoonist for both the Tribune and the Sunday Express. He also contributed social cartoons to a wide variety of magazines, including Punch, Radio Times and Tatler.

In 1949 he took over from G L Stampa as Punch's theatre illustrator, working with the critic Eric Keown. This involved working late at night after the theatre. Searle further complicated the task by caricaturing the actors, something previous illustrators hadn't attempted.

Searle indulged the St Trinian's girls until 1953, when (in Souls in Torment), he coolly slaughtered his cash cows by contriving an atomic experiment in the school chemistry lab. He was moving on, though the world wouldn't let St Trinian's die, and the fictional school went on to inspire five increasingly embarrassing films (for which Searle merely designed the posters).

He also gave up political cartooning in 1951 and followed his wife to the News Chronicle to concentrate on reportage. With Webb as writer, they covered Dr Edith Summerskill's 1951 election campaign for the Labour Party in Fulham, then started a series, Looking at London, which grew into a book. Not long afterwards, the couple established their own publishing house, Perpetua Books, in which Searle published his own work and that of friends and heroes, such as Toulouse-Lautrec and the French cartoonist André François.

Searle had established himself as Britain's foremost illustrator. He produced travel books with Webb (such as Paris Sketchbook, 1950) and Alex Atkinson (By Rocking-Chair Across America, 1959). Searle's serious commentary took him to Auschwitz, Communist Europe and to various countries with Webb again to document the post-war plight of European refugees (Refugees, 1960). In 1960 Life magazine sent him to Jerusalem for Adolf Eichmann's trial.

Searle made a cartoon film about the history of energy for the Standard Oil Company in 1957, which involved a visit to the Disney studios. Searle's loose, flowing style was said to have been a major influence on Disney's subsequent 101 Dalmatians. In 1955 he made his own acutely observed update of Hogarth's A Rake's Progress, which has been considered such an important work that the originals have recently been acquired by the British Library.

Searle lavished upon these multifarious disciplines a dynamic and beautiful draughtsmanship that was instantly identifiable as his own. His drawing style, though flamboyantly assured, can be seen on closer inspection to be an accumulation of nuanced, even hesitant marks, as though even the act of drawing a single line is an experiment in possibilities. Suspicious of his own fluency, Searle was known on occasion to draw with his fingers taped together in order to reintroduce difficulty.

His cartoon characters are almost always English: huge dowager ladies picking at tiny blackened fowl, while spiky waiters giggle maliciously behind their trays; ripe women whose black lips perch on their faces like butterflies; baffled, lovelorn trombonists; threadbare bank clerks with splinter feet... They wore delicately realised pointy shoes and seemed unaccountably oblivious to the abundant richness of their settings.

But despite his achievements, Searle wasn't happy. He felt trapped, both at home and at work. He came to realise that he didn't enjoy the limelight. Protective of his artistic freedom, he felt engulfed by the demands of work and stifled by the way British publications tended to pigeonhole cartoonists.

Neither did he take easily to the role of family man. He saw his marriage as that of two egotists, with Webb from 1960 increasingly occupied by a new editing job at Puffin. He had also fallen in love, with Monica Koenig, a French theatre designer. He waited until 1961, when his twins turned 14, left his family a note in their absence, and absconded to Paris with Monica. He didn't look back.

Searle had always felt himself to be an outsider. He was born in 1920 to a working-class family in Cambridge, and was deemed an oddity by his parents, as he was left-handed. Though not a part of privileged Cambridge, Searle, confident in his prodigious talent, was quick to utilise what the town had to offer. He was an observer, a shy young man in spectacles who drew its buildings, trawled its museums and bookshops, and absorbed its spirit of intellectual adventure. His first cartoons were published in the Cambridge Evening News when he was 15, the start of a productive relationship with the paper. By the time he was 16 he had made himself an indispensable component of the editorial team producing the university newspaper, Granta. Its editor, the historian Eric Hobsbawm, devised ways to sneak him into lectures, the better to pin down the dons with his spindly pen-strokes.

When war broke out, Searle enlisted in the Royal Engineers, and spent two years being moved around Britain. For a while he was stationed in Kirkcudbright, Scotland, where he befriended a local artist whose two daughters attended a progressive school called St Trinnean's. Naturally, he amused the girls with fanciful drawings of the place.

Searle's self-imposed exile after 1961 was a blow to Britain, though perhaps we deserved it for our lack of appreciation of his gifts as an illustrator. The French showed their gratitude for his years of residence there by granting him, in 1973, an exhibition at the Bibliothèque Nationale – the first non-French living artist to be so honoured.

In 1967 Searle secured a divorce from Webb, married Koenig and moved from Paris to the village of Tourtour in Provence. He turned his professional attention away from Britain, completing numerous assignments for Holiday Magazine in the US, and notching up more cover designs for the New Yorker than he had done for Punch. From 1995, he contributed regular visual commentaries to the French newspaper Le Monde.

He devised visual title sequences for various films, including Those Magnificent Men in their Flying Machines (1965) and Monte Carlo or Bust (1969).

With age, Searle's serious work, far from becoming complacent, tended towards the splotchy, acidic, and psychologically dangerous. "Anatomies and Decapitations" was a series of starkly disturbing paintings of distorted human shapes exhibited in the US. When Koenig was diagnosed with cancer (she recovered), he produced A Few Complexes (12 Pen Drawings on the Theme of Frustrations and Complexes), included in the 1978 book Ronald Searle, which were powerful and lurid explorations of human angst, fuelled by his anger.

The human condition, man's inhumanity, and the Earth's fragile ecology continued to be subjects that excited him. His refined sense of the absurd had never flagged since the day, as a boy, he saw a policeman sneeze in St Andrew's Street, Cambridge, and wondered how such a thing could be possible. However, to the outside world he appeared increasingly cantankerous, never meeting agents or editors, dealing with queries by fax alone, repulsing foot visitors and only emerging from the Searle eyrie in Haute Provence to fetch fresh supplies of champagne, his favourite tipple.

Ronald William Fordham Searle, cartoonist and illustrator: born Cambridge 3 March 1920; CBE 2004; married 1946 Kaye Webb (died 1996; one son, one daughter; marriage dissolved 1967), 1967 Monica Koenig; died Draguignan, France 30 December 2011.