Horatio Nelson: England (still) expects

This week sees the start of months of commemoration of a commander whose early strategies had misfired, who was ruthless with subordinates and who was reviled for a notorious affair. Yet the radical techniques he developed - which brought an epic victory over the tyranny of his age - and his embodiment of all that is heroic make him a man who still matters

A Spithead Review is a rare event, but on Tuesday the Queen will pass rows of British and foreign warships moored off Portsmouth, their colours flying. This great spectacle marks the start of the succession of regattas, parties, exhibitions and conferences being held across the country over the next four months to commemorate the battle of Trafalgar, fought off Cadiz 200 years ago this October. That decisive conflict, with 19 French and Spanish warships destroyed, taken or wrecked, is remembered today chiefly through the death of the Commander-in-Chief of the Mediterranean fleet, Vice-Admiral Viscount Nelson, on the quarterdeck of his flagship, HMS Victory. Every year, throughout the Royal Navy, Trafalgar night dinners are held on 21 October, with Nelson celebrated through the toast to "the immortal memory": but the Navy has not always remembered him so favourably.

At his death, Nelson was famed as the person who had transformed the largely indecisive naval battle of the 18th century into a chance for clear and definite victories. His part in the battles of Cape St Vincent, the Nile and at Copenhagen, as well as Trafalgar, were justly celebrated. Very soon after Nelson's death and funeral in St Paul's Cathedral in January 1806, the biographies began to appear. They have continued ever since, and now number well over a hundred. In the early years, these books were uncritical and laudatory, but in 1849 Thomas Pettigrew published letters which made it clear for the first time that Nelson had had a child by his mistress, Emma Hamilton. This did not suit the mid-Victorian ideas of heroism, and in the hierarchical and aristocratic Navy of the day, Nelson's reputation took a distinctly downward turn. It was rescued only by the geopolitical necessities of the 1880s, when Britain, challenged by France, Russia and then Germany, recognised the danger and when naval rearmament became the imperative: the British people needed to be reminded of past naval success and Nelson's image was invoked by politicians, authors and artists to bolster naval expenditure. Perhaps a high point came during the Second World War with Alexander Korda's film starring Laurence Olivier and Vivien Leigh, screened in America as That Hamilton Woman and in Britain as Lady Hamilton: it not only told the story Nelson's affair with Emma, but also showed Nelson resisting tyranny in the form of Napoleon. Audiences equated the emperor in the film with Hitler. Churchill is supposed to have said that that the film was worth two army divisions.

The switchback nature of our memories of Nelson match the complexities of his character. But in 2005 we are no longer content with the simplistic portrait of so many biographies, where Nelson is portrayed as the sugar-coated hero. His rise to fame is more complex than these biographies allow. While he was no grandee, his father being a country parson in Norfolk, Nelson had a great deal of help in making the right moves and getting good ships from two well-placed uncles. Though he was energetic, courageous and ambitious, he did not particularly shine as a junior officer, but promotion came early. A lieutenant at 18 and a half, a captain at 21, Nelson then made disastrous mistakes through a combination of self-belief and inexperience, which alienated their lordships at the Admiralty, and led directly to his being passed over for commands and to five years ashore on half-pay in the late 1780s.

He learnt his lesson. He became a shrewd politician and successfully manager of his own promotion throughout the 1790s. He charmed and impressed political leaders, his advancement being helped by the relatively weak and worn out generation of admirals above him. He was as adept at self-promotion in private as he was in public, for he wore his medals and orders at all times, and from the time of the Battle of the Nile, he would invariably draw crowds when he was travelling or walking down a street. He was a difficult subordinate, only happy when completely in command. When he became more senior, he was accessible to junior officers, and capable of acts of great generosity. Yet his punishment record of the crew of the Victory during his Mediterranean command between 1803 and 1805, indicates a ruthlessness not often emphasised. This was also evident in the treatment of his anxiety-ridden wife Fanny, whom he rejected, brutally, in favour of the sensuous and beautiful Emma Hamilton. Nelson's ruthlessness and impatience came to the fore at Naples in 1799, during the extinguishing of the short regime of the Neapolitan republicans, when he allowed his ships to be used by the royalists to round up the rebels, to the dismay of many throughout Europe.

But his success in battle cannot be denied. He was cool, quick-thinking and certain, with that gift of focused detachment when the battle became fast-moving and dangerous. When he was promoted to Rear-Admiral at the young age of 39, commanding captains who were much older, he evolved a consensual, delegated style of leadership, in vivid contrast to the centralised and none too successful methods of Rodney and Howe, the admirals of the previous generation. He forged relationships with his captains, using his trademark informality, taking them into his confidence. When it came to battle, they knew exactly what he wanted. As one captain wrote, "The predominant feeling was not fear of censure, but apprehension of not gaining his approbation." This confidence enabled him to take risks in battle. Nelson's methods of leadership are still studied today and they have wider application than just to the military.

After five years of war against the French, the ships and men of the Navy reached a peak of efficiency when Nelson arrived at the top. Gunnery, discipline and seamanship were of a high order, though the ships were worn out. After the misery of the mutinies of 1797, morale had largely been restored. Prize money remained a powerful incentive to all. The margin of superiority over the French and Spanish was never so marked as it was in the first years of the 19th century. At Trafalgar, the British, ship for ship, possessed the advantage. Nelson was the right man at exactly the right time.

But mysteries remain. While thousands of his letters survive, and their open, vigorous style make them a pleasure to read, he masks his feelings. Only for a short period in 1801, in letters to Emma Hamilton written while he was at sea in the Baltic and insanely jealous of the attentions she was paid by the Prince of Wales, did he commit violent feelings to paper. But we have only one side of the story for, with his eye on her reputation, he destroyed her letters.

Where did his extraordinary confidence and self-belief spring from? He came from a dull and undistinguished family. His mobile, driven face was difficult for an artist to capture, and no two portraits are alike. What you see is what you don't get. Unlike Marlborough, Wellington or Churchill, other leaders who define national identity, Nelson remains elusive, and therein lies his fascination.

Roger Knight's biography 'The Pursuit of Victory: the Life and Achievement of Horatio Nelson' is published by Allen Lane on 7 July