First Carlist War

The First Carlist War was a civil war in Spain from 1833 to 1840, the first of three Carlist Wars. It was fought between two factions over the succession to the throne and the nature of the Spanish monarchy: The conservative and devolutionist supporters of the late king's brother, Carlos de Borbón (or Carlos V), became known as Carlists (carlistas), while the progressive and centralist supporters of the regent, Maria Christina, acting for Isabella II of Spain, were called Liberals (liberales), cristinos or isabelinos. It is considered by some authors to be the largest and most deadly civil war of the period.

The main Carlist forces were split in three geographically distinct armies where Carlist support was strongest: 'North', 'Maestrazgo', and 'Catalonia', which by and large operated independently from each other. Several independent, but nominally Carlist bands also waged a guerrilla war in mountain areas as far south as La Mancha and Andalusia, but were derided as bandoleros (bandits) by the Christino liberal government.

Aside from being a war of succession about the question of who was the rightful successor to Ferdinand VII of Spain, the Carlists' goal was the return to a traditional monarchy, while the Liberals sought to defend the constitutional monarchy. Portugal, France and the United Kingdom supported the regency and sent volunteer and even regular forces to confront the Carlist army.