Lisbon Treaty of 1703

a treaty for a political and military alliance between Great Britain and Portugal against Spain and France in the War of the Spanish Succession. It was signed in Lisbon on May 16, proclaiming an “eternal alliance” between Portugal and Great Britain (art. 14). Great Britain undertook to help Portugal in the war against Spain and France with land and naval forces adequate to defend the coasts of Portugal and its possessions outside of Europe (arts. 1–10). Portugal agreed to the continuous presence of a specified number of English warships in all its ports in time of war or peace. This, to a significant degree, placed Portugal under the control of Great Britain. The English government made use of the alliance with Portugal to win trade concessions that delivered almost all Portuguese commerce into the hands of Great Britain. The treaty laid the foundation for an Anglo-Portuguese political alliance.