This incident, which the Australian historian Philip Dwyer uses to introduce his biography, illustrates two key aspects of the Napoleonic story. The first is the way the future emperor manipulated even the most unfavourable events to create a legend, a smokescreen of half-truths and sometimes outright lies that continues to obscure the man behind it. His report on the defeat at Arcola described him ‘tracing out himself, with flag in hand, the path to victory’. The story got better with the telling, and the portrait, which Bonaparte commissioned, faithfully reflects his imaginary triumph. It was reproduced in widely distributed engravings that made the young general’s image familiar to people all over France. He proved extraordinarily adept at using the press to influence public opinion, in a period when such demagoguery was relatively new. He did it again after the skirmish at Lodi, when some 350 French soldiers were killed taking another bridge from the retreating Austrian army: had they waited another day they could have strolled across. Yet this too Napoleon described as a major engagement, ‘the most brilliant of the entire war’. The 11,500-strong Austrian army became, in his account, 18,000, their casualties 3000 instead of 300. Engravings showed Napoleon leading the troops, even though he had played no role in the actual fighting.

Falsehood was one of the building blocks of his career, and there are many other examples: the famous painting of him crossing the Alps on a rearing white charger is another iconic illustration of his exploits, whereas in reality he went over the St Bernard Pass on a mule. But part of his skill in propaganda lay in his eye for the story and in the quality of his writing. He wrote many of the newspaper articles himself, using suspense and drama to inspire and excite his readers.

The second foundation stone of Bonaparte’s career was the extraordinary luck that he enjoyed. Early in his career, he several times escaped punishment for quite overt and deliberate misdeeds: he was denounced and summoned before the normally efficient Committee of Public Safety, but did not front up and seems to have been forgotten. He disobeyed instructions on a number of occasions, including a direct order to go to fight in the civil war in the west of France in 1795. Again he got off unscathed because war broke out in Italy and the Revolution had few experienced military officers they could send.

Napoleon seemed to lead a charmed life. At Arcola, he escaped death at least twice, from enemy fire and from drowning. In Corsica he was almost murdered in clan feuding for which he was partly responsible. On various campaigns he was to have perhaps a dozen horses killed under him, and he later survived several assassination attempts. The coup that brought him to power in 1799 almost failed, partly because at the crucial moment he was paralysed by fear or exhaustion, and only the quick thinking of his brother and sheer good fortune saved him from disaster and probable execution. Many times, it is true, he made his own luck, manipulating events to his advantage and positioning himself with skill. His return from his campaign in Egypt in 1799 was a masterpiece of good timing that positioned him to overthrow the previous régime and made people forget that he had abandoned his army at the other end of the Mediterranean. His life reads like an eighteenth-century novel, too fantastic to be real.

It was so extraordinary that an ambitious man might come to see in it the hand of Providence and to believe that greatness was his destiny. ‘The idea came to me that I could well become, after all, a decisive actor on the political scene … From that moment I glimpsed the goal and I marched towards it.’ One of the leitmotifs of Dwyer’s biography is the way Bonaparte came to see himself as a man destined to rule. Rightly sceptical of Napoleon’s own account (as emperor, he had key documents destroyed if they did not match his self-fashioning), Dwyer persuasively identifies a series of key turning points: forced departure from Corsica; the Italian campaign of 1796; the sometimes neglected Egyptian adventure. A visit to Ancona in 1797 seems to have triggered a vision of an Eastern empire and – for an ambitious young man with an eighteenth-century education and a taste for military glory – the dream of becoming a new Alexander the Great.

Yet there was a further dimension to Bonaparte’s rise: his utter ruthlessness where his own ambitions were at stake. From the very start, he told barefaced lies in order to promote himself and his family, or to escape punishment. He made promises that he never honoured, such as offering six acres of land to every soldier who would come with him to Egypt. He was contemptuous of the law and of the rights and liberties that the French Revolution was supposed to have brought: in elections to the Corsican National Guard in 1792, he bribed the voters (so did the other candidates) and kidnapped one of the commissaries overseeing the vote. Four years later, in Italy, he dealt with guerrilla resistance by ordering reprisals against the civilian population. The record in Egypt and Syria was worse. He did not spare his own soldiers, many of whom died of thirst in the desert. At Jaffa, Bonaparte ordered the execution of the entire garrison and, when 3000 enemy soldiers negotiated surrender terms and were taken prisoner instead, he had them killed in cold blood, mostly by bayoneting because of a shortage of ammunition. He also ordered the deaths of a large number of women who had been captured and raped by the French troops.

It is true that such atrocities were not unusual in wars of the period. One of the strengths of Dwyer’s account is that it explains Napoleon as a man of his time, dispassionately cutting away the romanticism and the teleology that characterise many accounts. It deals particularly well with his relationship with Josephine, neither ignoring nor privileging it but suggesting the way that love and jealousy meshed with other factors to drive and torment the young soldier. Dwyer draws on published sources more than on archival ones. Informed readers will not encounter much that is new, either in the detail or in the conclusions he draws: this is not a major reinterpretation of Bonaparte’s life. But it is a masterpiece of synthesis (if over 500 pages just on the early career deserve that term).

The writing is often very good. Above all, the portrait of Napoleon is compelling, one of a man driven by immense ambition yet given to moodiness and even depression, an individual possessing huge restless energy, talent and luck, and no scruples. With unknowing prescience and characteristic self-obsession, Bonaparte summed himself up in 1795 to Désirée Clary, the first woman he courted: ‘With a fiery imagination, a cool head, a strange heart and melancholic tendencies, one can shine among men like a meteor and disappear like one.’