Prince Balthasar Charles. Balthasar Charles, Prince of Asturias, Prince of Girona, Duke of Montblanc, Count of Cervera, and Lord of Balaguer, Prince of Viana was heir apparent to all the kingdoms, states and dominions of the Spanish monarchy until his death.
The only son of King Philip IV of Spain and his first wife, Elisabeth of France, he was baptized on November 4, 1629 in the Parish of San Juan, Madrid. His godparents were Infanta Maria Anna and Infante Charles, aunt and uncle of the newborn; Inés de Zúñiga y Velasco, Countess of Olivares sat on a crystal throne during his baptism, which was said to be the most precious jewel she had seen.
The Countess of Olivares, who was also chief lady-in-waiting to the Queen, worked as a governess to the prince, which gave rise to comments about the control that the Count-Duke of Olivares had on the heir. On 7 March 1632, he was sworn in before the nobility of Castile as His Majesty's Heir and Prince of these kingdoms of Castile and Leon, and others that are subject to these Crowns, united and incorporated, in a ceremony held at the Monastery of San Jerónimo el Real of Madrid.
His father soon began diplomatic efforts to seek a bride: Archduchess Mariana of Austria, daughter of Holy Roman Emperor Ferdinand III and his paternal aunt, Maria Anna, and therefore his cousin, being chosen. Another cousin, the daughter of his mother's sister, Henrietta Maria and her hus