Course of the War:
Don Pedro captured Oporto, but was besieged there for nearly a year. With assistance from outside he overcame the resistance of the enemy and entered Lisbon in July, 1833. A quadruple treaty was signed at London in April 1834, by which Spain and Portugal, assisted by Great Britain and France, engaged to drive both Miguel and Carlos from the Peninsula. A Spanish army marched against Miguel and the British fleet arrived. Miguel renounced the crown, and quitted the Peninsula. Don Carlos was conducted to London, but he escaped and appeared again in Spain at the head of his insurgents in July 1834. He gained several victories, and prepared to march on Madrid. Christina appealed to France for assistance, but Louis Philippe was reluctant to embark on the enterprise and refused. The war continued till at last General Espatero forced back the insurgents, the Carlists turned their arms against one another, and Don Carlos surrendered and crossed the French frontier.