Carlos María Isidro de Borbón (1788-1855) was a Spanish nobleman and a key figure in the Carlist Wars, which were a series of civil wars in Spain. He was the younger brother of King Ferdinand VII and claimed the Spanish throne after Ferdinand's death, opposing the succession of his niece, Isabella II. His claim was based on the belief that the Salic Law, which barred women from the throne, should be upheld. As a leader of the Carlists, Carlos María Isidro garnered support from traditionalist and conservative factions in Spain. His followers, known as Carlists, fought for his claim during the Carlist Wars, which lasted from 1833 to 1876. These conflicts were marked by deep political and social divisions in Spain, reflecting broader struggles between liberal and conservative ideologies.