Paul Methuen (diplomat) gained valuable diplomatic experience and the esteem of King Pedro. During two absences of his father he became chargé d'affaires, rising to Minister on his father's appointment as Lord Chancellor of Ireland in 1697. He was unable to prevent a Portuguese-French alliance in 1701. When his father returned to Portugal a special envoy in 1702, they were successful in breaking the alliance in 1703. The led to the Methuen commercial treaty between England and Portugal, the basis of Britain's monopoly of Portuguese trade for much of the 18th century. His father remained in Portugal as ambassador. In 1705, Methuen served
Treaty of Friendship, Commerce and Navigation Between Argentina and the United Kingdom former colony. The treaty also allowed British subjects to keep their religion, and to build their own churches and cemeteries. This was an unprecedented step in the history of the freedom of religion in Argentina, as it was the first time that a religion other than the Catholic Church was legally allowed in the country. The treaty set as well an agreement to stop the Atlantic slave trade. In the context of the dispute over the Falkland Islands (), Lowell S. Gustafson argues that by signing the Treaty without making any reservation about Argentina's settlement on the islands by 1825,