Wellington's celebrated Peninsular army played a vital role in the defeat Napoleon's French forces in Portugal and Spain. It is one of the most famous armies in military history. Yet the last large-scale examination of its structure and operation was written by Sir Charles Oman as long ago as 1913, and since then so much new material has come to light that a fresh account is long overdue. This important new study, which uses Oman's pioneering work as a foundation, provides a wide-ranging survey of the latest research into the subject, and it is a major contribution to the history of the Peninsular War.