No slouch when it came to handling humour, Groucho Marx called him a genius; in 1971, John Lennon announced that, along with Lewis Carroll, he was one of two people who had exerted the most influence on his life; Tom Wolfe called him the giant of the graphic netherworld; Cecil Day Lewis wrote him a dirge; S. J. Perelman was as devoted to his turn of phrase as he was to his nimbleness of line; Max Beerbohm wrote him a fan letter, and on the 26th October of this year, at the age of 65, Ronald Searle celebrates fifty witty years in print.

Searle has come a long way since his local paper, the Cambridge Daily News, published his first drawing at the age of fifteen. The trifle he earned helped to pay for his studies at the Cambridge School of Art - studies in the fiercely academic tradition of Tonks and the Slade, that of unremitting toil combined with minute, surgical observation. As crushingly oppressively as Searle found it at the time, he has since remained eternally grateful for the freedom it gave him to 'play' with his pencil and pen. By the time his studies were interrupted by the outbreak of war, Searle was already well-armed with a precocious grasp of drawing. He served seven years as soldier, and the war - in particular the period of captivity under the Japanese from 1942 to 1945 - provided him with the subject matter and the impetus to apply what he had learned. At the age of twenty-six he emerged from the experience to be swiftly recognized as a remarkable draughtsman with (not surprisingly) an almost oriental feeling for the purity of line. Academic success was soon overtaken by popular success as Searle, in an original and very personal way, merged his academic background with graphic satire and a wickedly sharp eye for the ridiculous, which rapidly brought him to international attention.

But to return to the teenager, and the war.

Very much against his will and after forty years of silence on the subject, Ronald Searle agreed to accept a tough assignment for the latter half of last year: to relive for those who could not know the story, the forty-two months he spent in Japanese captivity. Earlier in the year, he had presented to the Imperial War Museum four hundred drawings documenting those mostly unphotographed - virtually unrecorded - days during the Japanese invasion of South East Asia. They are now passing through various stages of conservation (de-acidization of paper, etc.) before they go on show to the public in March 1986. To coincide with this exhibition of the unknown Searle, a substantial number of the drawings will be reproduced facsimile in a lavish volume to be published by Collins (To the Kwai - and Back: War Drawings 1939-1945, March 1986) featuring not only around 200 pages of reproductions in colour but also about 20,000 words of background text. 'Too many background words for any artist,' says Searle. The story of his days in the Siam jungle and later, imprisonment in Changi gaol, took him over five months to write and his efforts to recall the exact circumstances under which each drawing was made also brought him a miserable five months of almost sleepless nights. In 1943 the young art student found himself involved in one of the most barbarous operations in the history of warfare, the building by prisoners of war of a supply railway to the Burma Front through some of the most hostile terrain and virtually impenetrable jungle known on this earth. Later dubbed the 'Thai - Burma Railway of Death'.

'My formation is rooted, I think, in those days of captivity,' he once said. 'To be precipitated into circumstances of almost total isolation, total brutality, total filth and disgust, and virtual slavery at the age of twenty-three inevitably and indelibly marks one's outlook on anything one relates to afterwards - if you were lucky enough to be counted among those few who had an "afterwards". To wake up many mornings with a thousand miles of jungle between you and the Allies, to find the fellow prisoner on each side of one dead, is more than salutary. One begins to clarify in one's mind the nuances of the word "mortality".'

Most of his fellow prisoners perished in that jungle or later in Changi: what kept Searle alive may have been an artistic lifebelt, the determination to carry out his self-appointed task of documenting what was happening, in the hope that one day it would be seen. To do, in fact, what Otto Dix and Goya, in their different ways, had done before him. With the essential difference that Searle was part of the drama and any work had to be done in secret and concealed with the help of his fellow prisoners. Concealed where the Japanese would not think (or care) to look - underneath the body, for instance, of a man dying of cholera.

Ten years ago, in a television interview, one of his friends who survived - the Australian writer Russell Braddon - gave a vivid picture of Ronald Searle at this time in a base camp in Siam, after coming out of the jungle:

When the Line was finished he was a sick boy. I remember that there was nothing much of him, that he was like a baby or a monkey or something. We thought he was dying and we - some of his remaining friends - used to put him out on a ground sheet in the sun. I don't know why, but we felt the sun would do something. He could barely move, and we had no food, he had dysentery, malaria and was covered in running sores, and each day we expected him to die. He was a tough little one, though: he wasn't going to. His mad Heath Robinson mentality got to work and he had us make a bamboo pipe so that when he had to urinate, he didn't soil himself. No one else in those camps had managed to devise their own sewage system. If you can imagine something that weighs six stone or so, is on the point of death and has no qualities of the human condition that aren't revolting, calmly lying there with a pencil and a scrap of paper, drawing, you have some idea of the difference of temperament that this man has from the ordinary human being.

The resilience of Ronald Searle was such that, a few months after his final release he was back in England - and this is where I first met him - living in a gleaming white cube of a room at 34 Tite Street, Chelsea, already preparing to embark on a career as a freelance artist. Later he discovered from Oscar's son Vyvyan Holland, that the house (previously number 16) had been the home of the Wilde family and that his own bedsitter (first-floor back) had been Oscar's library. 'That decided me to hone what wit I had, out of basic respect for the shadows on the walls,' said Searle.

We met many times that winter of 1945-46: sometimes in a small restaurant - George's? The Star? I forget now - where Thorn House now rears . . . at Vera Volkova's ballet class in West Street, where Karsavina sometimes looked in to pose her shopping basket . . . a dressing room at the Ambassadors (Sweet and Low) . . . my flat in Covent Garden. A major occasion was taking him to the first night of Roland Petit's Ballets des Champs-Elysées at the Adelphi on 9 April 1946, an event which in some ways may have influenced his career and future life: we belong to the same generation and the famous Kochno-Bérard-Sauguet ballet, Les Forains, probably sealed our love of France and the French.

During this time Searle was rapidly becoming famous and sought after. Although the girls of St Trinian's had been created before his captivity, in 1941, their moment along with the rest of Searle's macabre range of humour, came now: pictorial Victoriana was dead and post-war England was ripe for Searle. Between return-bouts of malaria he unleashed his graphic ferocity on the hapless public - and they loved it. Searle was away. He moved to a bigger studio, in 77 Bedford Gardens, on Camden Hill. Before too long he could afford to buy a house a bit further north, and he moved into 32 Newton Road in 1951. His first house, but naturally, no ordinary one. This had been designed by the young Denys Lasdun c. 1938, who was already showing some talent for the theatrical. Searle's studio on the whole of the topmost floor had a highly unconventional terrace attached to it, overlooking half of Paddington. As Searle said, if one had to overlook half of Paddington this was the way to do it. I remember - wineglass in hand - swaying on that high terrace with a slightly stunned, also happily swaying Searle, a few days after he had moved in with his wife, two children and ten thousand books. Any passing anxiety caused by additional responsibilities turned out to be quite unnecessary, for his life, excellently stage-managed as always, continued to move from strength to strength: one series of his books sold three-quarters of a million copies, he became a publisher in his own right, at Malcolm Muggeridge's insistence he joined The Table of Punch along with John Betjeman and Anthony Powell, and he darted back and forth across the Atlantic on film work in Hollywood and editorial work in New York and London. His career as a 'famous' artist was now unstoppable - until one day he quietly stopped it.

Contrary to much of what has been written about this move, the reasons are not at all obscure: they centred round the encroaching pressures of his non-stop work, his lifestyle and the necessity to pause for the first time since he came out of prison fifteen years before, to quietly reassess exactly the direction in which he was going and how he could best use his remarkable talent for graphic satire without squandering it. (He remembered Max Beerbohm telling him, 'I have a little talent, but I have used it well . . .'). First he needed to cut out the superfluities and concentrate entirely on exploring the range of his possibilities as an international and not a parochial satirist. For a start he needed to eliminate family responsibilities, and social demands.

Until now, most people have sought the cliché answer and have taken this as Searle 'doing a Gauguin' and he has never, as usual, bothered to correct this. But the fact that Searle takes his art seriously has never meant that he, by any stretch of the imagination, wished to be taken as a 'serious' artist. Searle is, and always has been, a one-hundred percent, single-minded graphic satirist, hypnotized by the unbounded possibilities of visual humour and restlessly pursuing his surgery of the deeper recesses of the anatomy of laughter. Any suggestion that Searle - with uncharacteristic loss of his own sense of humour - has ever thought of taking himself seriously, or of diverting himself from that straight and thorny path of graphic satire is nonsense - and I have it from the horse's mouth.

On 9 September 1961, Searle abandoned everything - his home, family, possessions, career, and arrived in France, penniless, but with a clear plan of his intention to start again from zero. His early days in Paris were a complete contrast to the all-demanding popular success he had known in England. 'In 1961 Paris was a good place in which to settle and rethink,' he says. 'The atmosphere was conducive to reflection. I've always felt at home there, and certainly on the Left Bank, more so than in London - which I love. Perhaps because I was born in a university town and learning was always part of the bread and butter. The eternal student in me, I guess. Anyway, so far as the bread and butter was concerned, if you were cold you could work in a café all day over a cup of coffee and if you hadn't got cooking facilities, the local baker would roast a bird for you if the occasion was grand - and Billy Bunter's postal order turned up.'

From 1963 things improved, as I was able to see for myself when I visited him in his fourth-floor flat at 4, rue Antoine-Dubois opposite the old medical school. Also he was with Monica. Monica his companion (and, soon after, his second wife) had been in Paris since 1951. She was English, a stage designer, an imaginative cook, brilliant linguist and apart from feeding him (and friends like me) well, she was able to do much to smooth the way of Ronald's reshaping of his life and take over most of the inevitable chores. A witty, beautiful and intelligent woman to whom Searle remains entirely devoted, and not least for her sense of humour . . .

The flat in the Latin Quarter became their base of operations and for the next fourteen years their working life was divided between Paris, Berlin and New York. Meanwhile French colleagues extended a big welcome to Searle, and it was Jean-Pierre Desclozeaux of the Nouvel Observateur who eventually had the idea of founding a society in his honour: 'Les Amis de Ronald Searle', which has the distinction of numbering among its twenty-eight founder members two circus clowns - including a Fratellini (it continues, basically to accept donations for aiding young artists short of necessities for their exhibitions). Later, Jean Adhémar, director of the Cabinet des Estampes, Bibliothèque Nationale, was the moving spirit behind the great retrospective at the BN in 1973, Searle being the first living foreigner to receive such homage - with all three floors of a wing to fill. The French Mint became his stamping ground when the director, Pierre Dehaye, suggested that he became a medallist for them, which he was for ten years. The Mint has now struck some twenty commemorative medals sculpted by Searle, but the first (at their suggestion) was a commemorative medal to Searle himself. Meanwhile over in the Marais, Michel Cassé's presses turn as the exclusive printer for the last twenty years of Searle's two or three hundred editions of lithographs.

The very English Searle's love of France - dating (we like to think) from Les Forains - does not exclude a delight in French follies and foibles. His letters never miss the latest delicious absurdity, or breath-taking Gallic mangling of the English language. His judgements on French (and other) artists make one regret that the once-planned Dictionary of Caricature was finally shelved as an unnecessary consumer of vital drawing time. Yet despite his obsession with work, Searle must be among the best informed and most well-read of artists. Rising at six to read French, English, American and German publications, not to mention the local and international press, he will move on to type a dozen letters before settling for ten hours at his drawing-board. Drawing of course, with the left hand (for this master of the pen is proud to be a 'cack-handed' Fenland yokel, whose ancestors rose extremely slowly out of the local bogs and mists - if we are to believe his introduction to his recent lavish album: Ronald Searle in Perspective (forty-five years of drawing), published by the New English Library in 1984 at £19.95, and worth it).

A constant student of the history of caricature, Searle has accumulated over the years a large collection of original drawings, beginning with the father of portrait caricature itself, Annibale Carracci (1560-1609). But you will find on his walls only work from the seventeenth, eighteenth and nineteenth centuries - Hogarth, Gillray, Richard Newton, Rowlandson and George Cruikshank starring. There is nothing of his own on the walls and nothing of his contemporaries, not even his old friend 'Vicky', some hundreds of whose letters he recently arranged to be conveyed to Philip Larkin for safe-keeping at Hull. But the choice comes from the necessity to remain aware of the 'roots' of his art. To be faced every day with substantial works that stand up to familiarity and microscopic examination. 'In the light of which', says Searle, 'much of my work and that of my contemporaries falls flat on its face.'

Among literary friends the late S. J. Perelman held pride of place. The first time they met, in a New York restaurant, Searle asked the waiter to direct him to the 'cloakroom'. Perelman exclaimed, 'My God! That's straight out of Baroness Orczy - where are the passing peasants?' They were friends for life. Although they have known each other since the 1950s, Samuel Beckett and Searle rarely coincide these days, although not too long ago Searle and Monica would travel to Ulm or Berlin for the opening of a German production that Beckett had directed. Searle has much in common with Beckett. Caricature is a weapon against injustice but like Beckett, even at his most savage, Searle never loses what Ben Shahn called his 'infinite toleration and sympathy for the human condition . . . for all those crotchety, malshapen, well-intentioned persons, labouring earnestly, arduously and with infinite difficulty through the barbed-wire entanglements of life, but never questioning their duty to go on.' Even when his feelings are too much involved with his subject, Searle never discards caricature. True, many of his youthful portraits of Japanese soldiers and their prisoners are remarkable for their calm and sympathetic understanding, but the object of that exercise was to present a factual document, nothing more.

To many of his admirers today, Searle means cats. A word of explanation here. In the manner of La Fontaine ('Je me sers d'animaux pour instruire les hommes') Searle uses animals for his own ends. He is therefore surprised when he receives fraternal greetings from cat-lovers, for the fact is that he doesn't like moggies but simply finds them a 'convenient international currency'. (If the St Trinian's girls were really Japanese in disguise as some have suggested - though not Searle - the cats are people in drag.) I once suggested to Searle that the French artist Grandville, nineteenth-century illustrator of La Fontaine, might have been his immediate inspiration: but Dr Searle went to the bookshelf and took down a 1618 edition of Della Porta's De Humana Physiognomonia comparing human and animal character, to show that the process had its roots well back in time. My fear is that Searle will kill off his cats as ruthlessly as he rubbed out the schoolgirls in 1953, knowing that he hates a subject to drag on until he loses interest. But let him be warned: thousands of his admirers would consider this an affront. Cats is delicate ground . . .

1967 was the year of the first of the Searle cat books. It was also the year he and Monica married at the British Embassy, Paris. The five guests who were let into the secret that evening at their friend Pierrette's restaurant, Gachoucha, included one English journalist: me. In the end the 1960s had not gone badly: the initial crisis was followed by recovery as Searle did his planned re-thinking and moved on. But the decade ended on a sombre note. Monica's New Year's Eve present was the news that she had cancer - and a deadly one at that. Three months would see her out, it seemed. So, never one to refuse a challenge, she opted to become a privileged front-line guinea-pig for Professor Léon Schwarzenberg, and off they went into the experiment.

For a while I moved over to Paris to be of some use as a telephone answering service, whilst Searle either lived at, or dashed back and forth from, the hospital. That was fifteen long and adventurous medical years ago. But the Searles and Léon (now a firm friend) still meet to crack a bottle of champagne over the result that also led a lot of other sufferers out of the condemned cell.

Inevitably this challenge changed - once more - the pattern of Searle's life, but although the 1970s became the Years of Cliff-hanging for them both, with little travel and fewer encounters with their friends, their semi-isolation in the heart of Paris during the seemingly everlasting treatment provided them with a ready-made bridge to their next (highly unexpected) move. In the mid-1970s and in mid-problems, they suddenly received notice from their ambitious young landlord to quit their home. They fought back, lost, packed, and left Paris, re-deploying to a small mountain-top in the foothills of the lower Alps. There, in place of the somewhat gruesome view into the bacteriological labs of the university medical school they enjoyed in Paris, they had the full sweep of the Maure mountains, a view that drifted on beyond the Mont Ste Victoire, along to the Luberons and into the Gard: a compensation for their lack of furniture (stuck in the garde-meuble until they could find enough money to have it join them) and lack of work (Searle had hardly sat down since New Year's Eve 1969). But Searle's faithful and well-loved friends Tessa Sayle in London and John Locke in New York - both also Searle's agents - soon solved that one and before too long the furniture was out of bail and the work and the champagne (Searle's engine oil) flowed fast and furiously again.

Now these one-time globe-trotting Parisians are virtually impossible to budge. They revel in the secrecy of their hide-out, casual visitors are firmly discouraged and their life is almost conspiratorial in its privacy. Their friends and the locals - mountain people - understand and co-operate. But, like education and intelligence, one should not confuse solitude with isolation. The Searles are not faintly isolated. Living as they do, both on borrowed time, they treat each day as a great big slice of cake to be savoured down to the final crumb. Consequently they have no time for those who leave half a slice on their plate for lack of appetite or interest. Searle's work is probably better than it ever was, and for the last decade he has taken to this cell-like, but totally unmonastic life, like some trout in a mountain stream, steadily moving towards source with every ounce of energy he can muster. Searle, who has been a major influence on succeeding generations of graphic artists in England and America has, in a certain sense, always remained a 'survivor' - a loner, indelibly marked by the slim chance that allowed him to return from one jungle and prepare him for the next. He may still sleep with one eye open and his hand at the ready for his pen, but he does so with a lashing of wit, and a touch of offbeat fantasy that has marked him for a long time now as one of the most original humorists of our time, and arguably the finest graphic draughtsman of this century.

And yet there is more.

In the course of my delving into what is visible of the man I have known for (my God, can it be?) forty years, I find that there is in the archives of the Ministry of Defence, a copy of a letter written to Searle in January 1957, by General Sir Charles Keightley, GCB, KBE, DSO, Commander of Allied Forces, Port Saïd Operations (Suez War), which reads:

Dear Searle,

Now that the Allied operations in the Middle East are over, I would like to thank you most warmly and sincerely for the services which you rendered. I was especially grateful to you for coming out at such short notice and being ready to do so much to help us.

The fact that the operations ended as quickly as they did does not detract from my personal gratefulness to you.

With my best thanks, and with all good wishes for the future.

Yours sincerely,

Charles Keightley.^*

Our Ronnie? Up there among the Suez brass? Are we seeing only the tip of the iceberg?

^*When I tackled Searle about this somewhat intriguing discovery, his reply was: that it was an extremely subtle move. That if Nasser came to hear that he (Searle) had joined Bernard Fergusson's staff in the Department of Psychological Warfare at HQ Cyprus, he would die laughing - which would of course, make it much easier to take the canal. I pass that on for what it is worth.

The Ronald Searle exhibition at the Imperial War Museum Gallery will be on until 6 July.