Although Patrick O'Brian was still writing 1,000 words a day in his secluded French farmhouse well into old age, there was an insatiable demand for yet one more instalment of his historical seafaring saga.

He wrote several books of non-fiction, including a biography of his friend the artist Pablo Picasso, and translated the work of several distinguished French authors, including Simone de Beauvoir and Andre Maurois.

However, it was his meticulous evocations of life on board ship in the Royal Navy during the time of Lord Nelson that made him a cult author.

The intensity of his characterisation, the complex elegance of his plotting and the brilliance of his prose inspired near worship among his devotees, including leading politicians, literary figures and showbiz celebrities.

His celebrated naval epic began with Master and Commander and continued with others such as The Hundred Days, The Thirteen Gun Salute and The Yellow Admiral.

The final instalment, Blue at the Mizzen, was published late last year and O'Brian was working on Volume 21 of the saga at the time of his death.

Two principal characters dominate the novels: the heroic Captain Jack Aubrey and his enigmatic shipmate, Doctor Stephen Maturin. Together, the pair chart their way through class difference, love rivalry and the demands of the Revolutionary and Napoleonic wars.

Popularity came late to O'Brian. His first story was published when he was 15, but Master and Commander didn't hit the bookshelves until 1969. Yet it was not until 1990 when the New York Times put him on their book review section cover that he first came to the notice of his, now insatiable, American audience.

In 1992 the Washington Post described him as "the best writer you've never heard of", and critics compared him with Melville and Conrad for his descriptive powers.

The collapse of Communism resulted in a change in literary fashion that worked to his advantage. In the 1990s he sold more than two million books and enjoyed a particularly strong following in America where 1,000 copies of each of his saga were sold monthly.

Patrick O'Brian overcame many obstacles to achieve his success. Much of his early fiction and classical studies were destroyed when his London home was bombed during the Second World War.

His father was a wealthy doctor whose own father had emigrated from Germany. Though born into an initially prosperous family, O'Brian suffered a lonely, sickly childhood, and saw his father fritter away the family fortune.

Though his poor health prevented his actually joining the Royal Navy, his imagination remained unfettered.

He was able to soak up classical tales of heroic voyage and research every aspect of naval life, affording him what he termed "the jewel of authenticity".

His French farmhouse, where he had lived alone since his wife's death in 1998, contained an exhaustive collection of 18th century naval chronicles. His 1810 copy of the Encyclopaedia Britannica was well thumbed.

Some speculate that the character of Maturin was based on O'Brian himself. They shared an apparently Irish background and a passion for natural history. They may have had more in common.

Maturin was involved in wartime espionage and there is a strong suggestion that O'Brian's notorious secrecy derived from his own experience working for the Political Intelligence Department during the Second World War, supplying 'black' propaganda to undermine German morale.

His origins, too, remain shrouded in mystery. His claim that he was born in Ireland appear to be untrue. Research has uncovered that he was born in the English county of Buckinghamshire, as Richard Patrick Russ, although he probably spent some of his early life in the west of Ireland.

O'Brian was married twice. His second wife, Mary, was the mother of the historian Count Nikolai Tolstoy, from an earlier marriage.

O'Brian was a fluent speaker of French and Catalan. He defended his reticence by citing Maturin's own opinion that "question and answer is not a civilised form of conversation".

Whatever private questions Patrick O'Brian left unanswered, he made up for it in his novels, so rich in detail that recipe books of the fleet's dishes and CDs of the music shared by Aubrey and Maturin have both been published.

The British Library dedicated a bibliography while he was still alive, and the writer AS Byatt once said, "If Jane Austen's naval brothers had written novels, they might have written the novels of Patrick O'Brian."