After Macbeth he began to film Othello. The work was to become the kind of odyssey which was henceforth to characterize Welles' life. The filming dragged on from 1949 to 1952, moving from location to location across Morocco and Italy. When money ran out, work would stop - to recommence when funds came in and cast could be reassembled.

If the difficulties of production again show in the uncertainty of the overall conception, at least here Welles could call on more talented associates than he had been able to for Macbeth : his old friend and early mentor from his youthful days as an actor in Dublin. Micheal MacLiammoir, creates a wonderful, feline Iago whose malice, the film infers, is the product of sexual impotence.

Welles now seemed doomed to endless wandering, leaving in his wake a host of uncompleted or abortive projects. In 1955 he began to film Don Quixote in Mexico and Paris, with himself as the Don and Akim Tamiroff, one of Welles' favourite actors, as Sancho Panza, but the film was never completed. Other projects talked of along the way include the Biblical stories of Noah, Abraham and Salome; two more Shakespeare subjects, King Lear and Julius Caesar (eventually produced in 1953 by an old Mercury Theatre collaborator, John Houseman, with Joseph Mankiewicz as director); Pickwick Papers and (ironically) The Odyssey ; Catch-22, which was eventually made by Mike Nichols in 1970. with Welles himself playing General Dreedle.

Even in the days of his childhood encounters with Shakespeare, Welles showed a special affection for larger-than-life characters. Mr Arkadin (1954) is a monster on the lines of Citizen Kane, a man of great wealth and power, who, unlike Kane, hires his own investigator to reconstruct the history of his mysterious career. This is, it is revealed, a test to establish if Arkadin's ultimate secret, the past guilt he most wants to conceal, is safe from detection. When it proves not to be, Arkadin realizes that the man must be silenced for good.

For many of Welles' admirers Touch of Evil (his last attempt to come to terms with the Hollywood studio system) is his masterpiece. Welles plays Hank Quinlan, a fat, decaying, crack cop, whose sense of deistic superiority leads him to frame people whom his 'infallible' instinct tells him are guilty. Welles sets the action in a border town of nightmare seediness, whose other inhabitants include Marlene Dietrich as a languidly philosophical madame, apparently a one-time flame of Quintan's, and Akim Tamiroff as the patriarch of a bizarre gang of hoodlums.

For years Touch of Evil was regarded as yet another example of Hollywood's legendary humiliation of creative genius: Universal studios' editors were alleged to have butchered Welles' original version. More recently, however, this has been reconstituted, and it is arguable that the Universal conception was actually an improvement; by leaving out some too-literal explanatory scenes, the cuts enhanced the sense of mystery and metaphysic which is the film's great attraction.

Le Proces (1962, The Trial), a Franco-Italian- German co-production, was shot in Paris and Zagreb. Much admired on its first appearance, it now seems one of Welles' least successful works. His own evident philosophical distance from Kafka results not so much in invigorating tensions as in excessive debate: for an Orson Welles picture it is, unusually, often tediously talkative. Visually the film is remarkable. Much of it was shot in the abandoned buildings of the Gare d'Orsay in Paris: the old railway station, often bathed in swirling mists, provides some stunning images.

Thanks to Spanish and Swiss finance, Welles was next able to return to Shakespeare with a film that may well remain, alongside Citizen Kane, his monument - Chimes at Midnight (1966). In a textual adaptation so brilliant that even the most demanding Shakespearean cannot fault it on grounds of scholarship, Welles assembled scenes from Richard II, Henry IV Part I and II, Henry V and The Merry Wives of Windsor, along with a commentary taken from the Chronicles of the Elizabethan historian Holinshed, to create a wholly new work which might be alternatively titied The Tragedy of Sir John Falstaff. Without any violence to Shakespeare's own, essentially comic, vision of Falstaff, Welles extracts a character that is heroic in his humour, generosity and goodness, flawed perhaps, but finally tragic in his incomprehension of the ingratitude of the great and powerful.

Over the years Welles acted indefatigably - often appearing in two or three films per year. Some of his roles - in Jane Eyre (1943), The Third Man (1949), Compulsion (1959) and Catch-22, for example - are memorable; all are enjoyable: none is without a conscientious intelligence. Often, however, Welles' willingness to accept parts in the most inconsiderable material - from TV commercials to Casino Royale (1967) - looks positively cynical. His majestic, unflawed performance as Falstaff, . however, demonstrated that, to whatever extent he might have prostituted his talent to the service of much lesser creators, he had kept intact and pure his gifts as an interpreter.'

Histoire Immortelle (1968, Immortal Story), adapted from a tale by Isak Dineson (the pseudonym of Karen Blixen), provided him vith another of the monsters he loves: a man like Kane and Arkadin, rich and powerful in the worldly sense but troubled by a secret sense of incompleteness. This old man, Mr Clay, is the embodiment of the traditional sailors' legend of the rich man of Macao who invites a young mariner to sleep with his beautiful wife (played by Jeanne Moreau), and fulfil the marital function of which he is himself incapable. Brief, classical and near-perfect, this film was Welles' last completed formal story film.

His wanderings continued. He acted in Bondarchuk's Waterloo (1970) and Chabrol's La Decade Prodigieuse (1971, Ten Days' Wonder). His rich, inimitable voice and superb diction were constantly in demand for film commentaries; and it was thus that he "came to work with Francois Reichenbach. Out of their collaboration came the delicious, enigmatic Verites et Mensonges (1973, F for Fake). Welles was fascinated by some 16mm footage Reichenbach had shot for a TV series on fakers, with the celebrated art forger Elmyr de Hory and Clifford Irving, who, subsequent to the original Reichenbach film, had become famous as the faker of Howard Hughes' 'autobiography'. To these, Welles added his own fakes (in which he included his role in the radio production of War of the Worlds which, over thirty years earlier, had fooled thousands of Americans into thinking that the USA was under attack by Martians). Welles orchestrates this material so as to entice the spectator into a fascinating labyrinth.

'I do not work enough'. I am frustrated. Do you understand?'