partisans of Don Carlos (1788–1855) and his successors, who claimed the Spanish throne under the Salic law of succession, introduced (1713) by Philip V. The law (forced on Philip by the War of the Spanish Succession to avoid a union of the French and Spanish crowns) was abrogated by Ferdinand VII in favor of his daughter, who succeeded him (1833) as Isabella II. Ferdinand's brother, Don Carlos, refused to recognize Isabella and claimed the throne.
A civil war followed (First Carlist War, 1833–40), and in the hope of autonomy, most of the Basque Provs. and much of Catalonia supported Carlos. The Carlists' conservative and clericalist tendencies gave the dynastic conflict a political character, since the upper middle classes profited from the sale of church lands and supported Isabella. The Carlists enjoyed many early successes, especially under their great general, Tomas Zumalacarregui. After he was killed (1835) in battle, the greater strength of the Isabelline forces gradually made itself felt. In 1839 the Carlist commander Rafael Maroto yielded, but in Catalonia the Carlists under Ramón Cabrera continued the struggle until 1840.
Don Carlos's son, Don Carlos, conde de Montemolín (1818–61), made an unsuccessful attempt at a new uprising in 1860. Montemolín's claims were revived by his nephew, Don Carlos, duque de Madrid (1848–1909), after the deposition (1868) of Isabella. Two insurrections (1869, 1872) failed, but after the abdication (1873) of King Amadeus and the proclamation of the first republic, the Carlists seized most of the Basque Provs. and parts of Catalonia, Aragón, and Valencia. The ensuing chaos and brutal warfare of this Second Carlist War ended in 1876, over a year after Alfonso XII, son of Isabella, was proclaimed king. Don Carlos escaped to France.
In the next half century many defected from Carlist ranks, and several rival groups formed. Pressure against the church by the second republic (1931–39) helped revive Carlism, and the Carlists embraced the Nationalist cause in the Spanish civil war (1936–39). Under the Franco regime Carlism was for many years an obstacle to plans for restoring the main branch of the Bourbon dynasty, but in 1969, Franco overrode Carlist objections and named the Bourbon prince Juan Carlos I as his successor.