April 22
Signed in London is the Treaty of the Quadruple Alliance between Pedro, Regent of Portugal, George IV of the United Kingdom, Louis Philippe of France and Maria Cristina, regent of Spain
Britain, France, Spain and Portugal united against Miguel and his uncle and brother-in-law Carlos Isidro de Bourbon.
The plenipotentiaries to the Treaty were Cristóvão Pedro de Morais Sarmento, Miraflores, Talleyrand and Palmerston.