Napoleon's invasion of the Iberian Peninsula brought Spain, Portugal, and Britain into a close, if sometimes uneasy alliance. When an expeditionary force led by General Sir Arthur Wellesley, later the 1st Duke of Wellington, disembarked in Portugal in August 1808, the British Army had been at war with France for five years. If the experience gained during campaigns on five continents had sharpened the efficiency of the Commissary Department, whose staff supplied and transported its rations, Wellington might not have complained after only one week in Portugal: I have had the greatest difficulty in organizing my commissariat for the march. The logistic challenges faced by the Duke of Wellington during the Peninsula War were daunting. The role logistics played in deciding the outcome of the war in the Peninsula as well as detailing the needs of the troops is important in understanding how the war was conducted. The procurement, transport, distribution, and payment of supplies for the use of the Anglo-Portuguese Army during the Peninsula War played a direct role in determining its final outcome.