Nelson's victory at Trafalgar on 21 October 1805 was a pivotal event in European history. But Trafalgar was not simply an isolated battle fought and won in an afternoon - the naval campaign had in fact begun more than four years before. This extraordinary period, following Napoleon's threat to invade England in 1801, came to be known as The Great Terror, and Britain was on the alert. As the Grande Armee faced a Dad's army of English volunteers across the Channel, a secret war of espionage and subversion was fought in the shadows. New weapons - rockets, submarines and torpedoes - were developed. Drawing on diaries, letters and newspapers, Tom Pocock paints a vivid picture of the years from 1801 to 1805, and of people caught up in these events: Nelson himself as he blockaded the French at sea for two unbroken years, his love Emma Hamilton waiting at home, Jane Austen and her naval brothers, the diarist Fanny Burney, the admirals, generals and politicians, as well as the lesser-known men such as Fulton, Congreve, Moreau and Pichegru who waged the secret war on either side of the Channel.