On 21st of August 1808, the 39-year-old Sir Arthur Wellesley (later to become the Duke of Wellington) stood at the head of an Anglo-Portuguese army numbering approximately 14,000.
His army was positioned on the blind side of a slope, awaiting the advance of a French Army under General Jean-Andoche Junot, that outnumbered him by between 3,000 and 6,000.
He held his men steady and waited until the French crested the hill and descended on this side to within range. Only then did he open fire.
This deployment of an army on the blind side of a hill became known as the ‘reverse slope tactIc’. At Vimeiro, it proved to be immensely successful and Wellesley subsequently made frequent use of it throughout the Peninsular War.
That the future Duke of Wellington should be in command of the combined British and Portuguese forces at this juncture, however, was an accident of Fate.