
Appointed to reorganize the Portuguese armed forces in 1809, Beresford commanded the Allied forces at the Battle of Albuera in 1811 and remained commander in chief and marshal general of all the Portuguese armies until 1820.
Beresford was born on 2 October 1768, the illegitimate son of the Marquis of Waterford. His younger brother became Rear Admiral Sir John Poo Beresford. He attended a French military academy in Strasbourg and was commissioned into the 6th Foot at the age of seventeen, serving with his regiment in Canada where he lost the use of an eye in a shooting accident in 1786. In 1789 he purchased a lieutenancy in the 16th Foot. He saw active service with Sir John Moore and Admiral Alexander Hood in Italy and at the siege of Toulon, respectively.