Intelligence is often the critical factor in a successful military campaign. This was certainly the case for Arthur Wellesley, the Duke of Wellington, in the Peninsular War. In this book, author Huw J. Davies offers the first full account of the scope, complexity, and importance of Wellington’s intelligence department, describing a highly organized, multifaceted series of networks of agents and spies throughout Spain and Portugal—an organization that was at once a microcosm of British intelligence at the time and a sophisticated forebear to intelligence developments in the twentieth century.

Blind cyclops : Britain's intelligence system in the eighteenth century --The house of cards : Arthur Wellesley, the development of military intelligence and the origins of the Peninsular War -- Diplomats as spymasters : agent and spy networks in Spain and Portugal -- Wellington's military intelligence network -- Intelligence and the retreat to Torres Vedras, 1809-1810 -- Stalemate and intelligence development in 1811 -- The limitations of intelligence : the invasion of Spain, 1812 -- Tactical and topographical intelligence : Wellington's mapmakers and the Vitoria Campaign 1813-1814.