Carlos María Isidro was a Spanish nobleman born on January 29, 1788. He was the younger brother of King Ferdinand VII and a prominent figure in the Carlist Wars, which were a series of civil wars in Spain during the 19th century. Carlos claimed the Spanish throne, opposing his brother's rule and the liberal government that emerged after the Peninsular War. His claim to the throne was based on his belief in the traditionalist and absolutist principles of the Spanish monarchy. Carlos María Isidro's supporters, known as Carlists, fought for his cause, leading to significant political and social conflict in Spain until his death on March 10, 1855.