The Dos de Mayo Uprising of Spain against Napoleon found Spencer in command at Gibraltar. On his own initiative he sailed for Portugal and arrived at Mondego Bay on 5 August 1808. The force that he brought with him were 946 men of the 6th Foot, 806 soldiers of the 29th Foot, 874 troops of the 32nd Foot, 948 men of the 50th Foot, 929 soldiers of the 82nd Foot, and 245 artillerists. All infantry units consisted of 1st Battalions, except the 29th which was not organized into battalions. At Mondego Bay he joined his force to the 8,123 troops that General Arthur Wellesley brought from Cork in Ireland.