Based on previously-unpublished personal letters and military records, this biography provides a unique insight into the life, ambitions, opinions, and actions of Wellington's most trusted, professional, and thoughtful staff officer, described as ‘the only man received into the unlimited confidence of Lord Wellington'. It is a full and frank story of one of the most respected and admired soldiers of his generation, his service in the Low Countries, Ireland, West Indies, and Egypt, and his importance in the Peninsular War. Murray's development of the Quartermaster General's department into an impressively efficient operation, touching on almost every aspect of the Army's movement, topographical and military intelligence, and preparation for battle, was of immense value to Wellington.