Peninsular War - Role of Intelligence

Role of Intelligence

Intelligence played a crucial role in the successful prosecution of the war by the Allies after 1810. Spanish and Portuguese guerrillas were asked to capture messages from French couriers. From 1811 onwards, these dispatches were often either partially or wholly enciphered.

George Scovell of Wellington's General Staff was given the job of deciphering them. At first, the ciphers used were fairly simple and he received help from other members of the General Staff. However, beginning in 1812, a much stronger cipher, originally devised for diplomatic messages, came into use and Scovell was left to work on this himself. He steadily broke it, and the knowledge of French troop movements and deployments was used to great effect in most of the engagements described above. The French never realised that the code had been broken and continued to use it until their code tables were captured at the Battle of Vitoria.