The year 1737 saw the death of Walpole's close friend Queen Caroline. Though her death did not end his personal influence with George II, who had grown loyal to the Prime Minister during the preceding years, Walpole's domination of government continued to decline. His opponents acquired a vocal leader in the Prince of Wales who was estranged from his father, the King. Several young politicians including William Pitt the Elder and George Grenville formed a faction known as the "Patriot Boys" and joined the Prince of Wales in opposition.
Walpole's failure to maintain a policy of avoiding military conflict eventually led to his fall from power. Under the Treaty of Seville (1729), Great Britain agreed not to trade with the Spanish colonies in North America. Spain claimed the right to board and search British vessels to ensure compliance with this provision. Disputes, however, broke out over trade with the West Indies. Walpole attempted to prevent war but was opposed by the King, the House of Commons, and by a faction in his own Cabinet. In 1739 Walpole abandoned all efforts to stop the conflict and commenced the War of Jenkins' Ear (so called because Robert Jenkins, a Welsh mariner, claimed that a Spaniard inspecting his vessel had severed his ear).