What is "carlism"

Carlism (; ; ; ) was a traditionalist and legitimist political movement in Spain seeking the establishment of a separate line of the Bourbon dynasty on the Spanish throne. This line descended from Don Carlos, Count of Molina (1788–1855), and was founded due to dispute over the succession laws and widespread dissatisfaction with the Alfonsine line of the House of Bourbon. The movement was at its strongest in the 1830s but had a revival following Spain's defeat in the Spanish–American War in 1898, when Spain lost its last remaining significant overseas territories of Cuba, Guam, the Philippines, and Puerto Rico to the United States.

An exceptionally long-lived movement, Carlism however also had a lot of opposition from other royalists who acknowledged that the successors of Isabel II of Spain had a legitimate right to the throne, being the senior heirs general of king Charles IV of Spain. Moreover, if the semi salic inheritance, which was used by the Carlists to justify their claim to the throne, was applied, then the Bourbons would not have come to the Spanish throne in the first place. After all, upon the death of the habsburg king Charles II of Spain, semi salic agnatic succession would have meant that the Habsburg Charles VI, Holy Roman Emperor would have become king of Spain and his daughter Maria Theresa and her successors would have become Spanish monarchs. The semi-salic law would have allowed this given the fact that Maria Theresa was the last member of the house of Habsburg.

Carlism was a significant force in Spanish politics from 1833 until the end of the Francoist regime in 1975. In this capacity, it was the cause of Carlist Wars during the 19th century, and an important factor in the Spanish Civil War in the 1930s. Today, Carlists are considered by some to be a fringe entity, with Carlist claimants "supported only by the most reactionary of the Spanish nobility," though this continues to be disputed.