No D'Artagnan could be a more engaging hero than Alexandre Dumas. His own life, and his career, with its spectacular successes and reverses, its links with great historical events, from the barricades of 1830 to Garibaldi's march on Sicily, had all the flamboyance of his novels. Even his antecedents were of the stuff of romance, and F. W. J. Hemmings, in this new biography, draws on recently published research to tell us far more than has previously been possible of Dumas' paternal origins.

Dumas' father was the son of a Haitian slave and the French marquis de la Pailleterie, a ne'er-do-well who, having disappeared for 27 years in San Domingo, had returned to France to claim his title and inheritance.

The marquis brought with him his 15-year-old son Thomas-Alexandre, leaving three older children behind. Alexandre Dumas probably never knew he had an uncle and aunts in the West Indies, his father having chosen not to mention them.

The young Thomas-Alexandre, after having a quarrel with the marquis, joined the army as a private, using his mother's name of Dumas in order not to discredit his aristoratic surname. He proceeded to cover it with glory, rising to the rank of general under Napoleon but eventually falling foul of the emperor and returning disgraced and in ruined health to his family in Villers-Cotterets, where he married the daughter of a local innkeeper. Here Alexandre Dumas was born in 1802, and with the death of his father not long after, had the family name to make all over again.

The story of Dumas' early years, his arrival in Paris and his first great triumphs as a dramatist are recounted in his memoirs (which sadly stop at 1832) with characteristic zest and sparkle. As if determined not to be carried away, Hemmings quotes from them very sparingly (Andre Maurois, in "Les Trois Dumas," used quotation much more freely). Sometimes, when a snatch of Dialogue or quoted comment would bring a scene to life, there is a feeling of excitement missed. But Hemmings' account, though restrained, is always convincing and here, as throughout the book, he is thoroughly at home in 19th-century France. h

Dumas was nearing his 40s when he made the transition from playwright to novelist. The idea of publishing popular fiction by installments in the daily press had been pioneered in 1836; by the 1840s the mania for romans feuilletons had reached its height. Dumas took full advantage of it. His prodigious output became legendary: One cartoonist showed him at his desk with four pens in each hand and a waiter ladling soup into his mouth. Hemmings is particularly interesting about Dumas' working methods and his relations with his collaborators. Dumas' attitude to his literary property, he remarks perceptively, was on par with his insouciant attitude to money.

Dumas' novels made him a world figure. As the author of "The Three Musketeers" and "The Count of Monte Christo" he was received like a prince wherever he traveled; Hemmings describes his various journeys -- whether to Russia, North Africa or following in the steps of Garbaldi -- amusingly and well. Dumas' plans to visit the United States never materialized -- partly, it appears, because he was dubious about his reception as a man of mixed ancestry, but also, as the American consul in Paris explained, because his domestic arrangements were so extremely French. "When I asked him if he spoke English, "No,' he said, '. . . but my mistress is English and I shall pick it up very soon.'"

As prodigious in love as he was in literature, Dumas' conquests were past numbering. Careless and good-natured, he probably never realized the suffering he sometimes caused; Alexandre Dumas fils in his autobiographical novel "L'Affaire Clemenceau" recalled the Persecutions he endured at school as an illegitimate child. He did not hold it against his father -- "my father," he said, "is a great big child that I had when I was very young" -- but in middle age he came to disapprove of his father's dissolute ways and to avoid him as much as possible. Nonetheless it was with his son that Dumas spent the months of his final illness and to him, in his last days, that he recounted a melancholy dream. He had been standing on a mountain made up of all his books, piled like blocks of masonry upon each other; it had crumbled slowly beneath his feet leaving nothing but a heap of stones." 'Alexandre," he said, 'on your soul and conscience do you think anything of mine will survive?' Greatly moved, his son reassured him. They embraced, and neither of them referred to the subject again." Dumas died a few days later.