 Alberoni now attempted to offset British in the Mediterranean by sponsoring a Jacobite landing to divert their naval resources; he also sought to end the 1716 Anglo-French Alliance by using the Cellamare conspiracy to replace the current French Regent the Duke of Orleans with Phillip of Spain.However, he failed to appreciate that Britain was now powerful enough to maintain naval superiority in the Mediterranean and the Atlantic while France declared war on Spain in December 1718 on discovery of the Conspiracy.France invaded eastern Spain and in October 1719 a British naval expedition captured the Spanish port of Vigo; they landed 6,000 troops, held Vigo for ten days, destroyed vast quantities of stores and equipment and then re-embarked unopposed.