While the paternal lineage of King Juan Carlos is well known and traces back to Queen Isabella II, his maternal ancestry is equally rich and diverse. It connects the Spanish monarchy to the royal houses of Brazil, Portugal, and former Czechoslovakia, as well as to aristocratic lineages of Poland, creating a complex web of European dynastic ties.
Juan Carlos’s mother, María de las Mercedes de Borbón y Orleans, was a key figure in this story. Her ancestors belonged to the Bourbon-Two Sicilies branch and the Orléans house. Among her notable relatives were the last Queen of Portugal, Amélie of Orléans, as well as the Counts of Paris, who laid claim to the French throne. Additionally, through her mother, she was connected to the German duchy of Mecklenburg. This branch is also directly linked to the Spanish throne through Queen Mercedes, consort of Alfonso XII, whose mother, Luisa Fernanda de Borbón, was the sister of Queen Isabella II.
The family of the future king’s mother spent much time in Spain, particularly at the Palacio de San Telmo in Seville, which belonged to her maternal great-grandparents, the Dukes of Montpensier, as well as at the Palacio de Villamanrique de la Condesa. María de las Mercedes herself was an honorary elder sister of the renowned Sevillian religious brotherhood Hermandad de la Macarena.
Juan Carlos’s maternal relatives, the descendants of Infante Carlos Tancredo from two marriages, formed several branches of the Bourbon family, which, despite marriages with members of foreign dynasties, maintained close ties with Spain. For example, Alfonso de Borbón-Sicilia, the eldest son of Carlos Tancredo, married Princess Alicia de Borbón-Parma in 1936. Their middle son, Carlos de Borbón-Sicilia y Borbón-Parma, was among the children selected to study alongside young Juan Carlos in Madrid.
Another branch of the family is connected with Eastern Europe. The descendants of Infanta Isabel Alfonsa moved to Czechoslovakia after her marriage. However, after her husband, Jan Zamoyski, was arrested by the Gestapo, the family was forced to return to Spain. The Zamoyski-Bourbon couple had four children, who continued the family line.
Juan Carlos’s mother’s younger sister, Infanta Esperanza de Borbón-Sicilia y Orleans, married Prince Pedro Gastão de Orléans-Braganza, a great-grandson of the last Emperor of Brazil. Their children were born in Brazil but always maintained close ties with European royal families, including the Spanish.
