Quadruple Alliance signed by Spain, France, Portugal and the United Kingdom

Background. The treaty emerged from a context of political instability in Iberia. In the United Kingdom, the Whigs had recently imposed the Great Reform Act in 1832, broadening the parliamentary regime. The alliance sought to secure the positions of liberal monarchs against rival Infantes, specifically Miguel in Portugal and Carlos in Spain, who were viewed as threats to the established order.

Terms and Implementation. The core obligation was the expulsion of Infante Miguel from Portugal and Infante Carlos from Spain. Economic compensations included plans for Spain's inclusion in the British commercial system. However, these economic terms did not materialize; a commercial treaty was signed in 1835 but never ratified. The alliance became effective in 1836, requiring troop withdrawals due to internal uprisings in Portugal.