Antonio Ponce de Santa Cruz (1561–1632) was the court physician in the royal courts of Philip III

Philip III of Spain

Philip III , also known as Philip the Pious, was the King of Spain and King of Portugal and the Algarves, where he ruled as Philip II , from 1598 until his death...

 and Philip IV

Philip IV of Spain

Philip IV was King of Spain between 1621 and 1665, sovereign of the Spanish Netherlands, and King of Portugal until 1640...

. Antonio was the son of Alonzo de Santa Cruz

Alonzo de Santa Cruz

Alonzo de Santa Cruz was a Spanish cartographer, mapmaker, instrument maker, historian and teacher. He was born about 1505, and died in November of 1567...

 (1505–1567), a famous Spanish cartographer, instrument maker and historian.

Antonio was also a university professor at the University of Valladolid

University of Valladolid

The University of Valladolid is a public university in the city of Valladolid, province of Valladolid, in the autonomous region of Castile-Leon, Spain...

 and a clergyman. He was interested in lycanthropy

Werewolf

A werewolf, also known as a lycanthrope , is a mythological or folkloric human with the ability to shapeshift into a wolf or an anthropomorphic wolf-like creature, either purposely or after being placed under a curse...

, free will, and the role of love in causing madness. As an expert on mental illnesses, he was charged with treatment of Prince Carlos

Don Carlos, Prince of Asturias

Carlos, Prince of Asturias, also known as Don Carlos , was the eldest son and heir of King Philip II of Spain. His mother was Maria Manuela of Portugal, daughter of John III of Portugal. Carlos was mentally unstable and was imprisoned by his father in early 1568, dying after half a year of solitary...

.

He published his father Alonzo's book Dignotio et cura affectuum melancholicorum (Diagnóstico y tratamiento de las afecciones de los melancólicos) about the diagnosis and treatment of melancholy posthumously in 1622.
He published the first Spanish treatise on epilepsy in 1631, Praelections Valliosoletanae.

Some have suggested that Antonio was friendly with Miguel de Cervantes

Miguel de Cervantes

Miguel de Cervantes Saavedra was a Spanish novelist, poet, and playwright. His magnum opus, Don Quixote, considered the first modern novel, is a classic of Western literature, and is regarded amongst the best works of fiction ever written...

, given their mutual interests and similarities in the condition described in Cervantes' book El Licenciado Vidriera (the lawyer of glass), and those in Antonio's book on melancholy.