In the early 17th century, a young novice vanished from a convent in Spain, leaving behind a habit and a predetermined life of religious seclusion. Years later, a fierce soldier emerged in the Americas, known for his deadly swordsmanship and aggressive temper.
This soldier, who rose to the rank of Lieutenant in the Spanish army, was actually the same person. For decades, Antonio de Erauso deceived an empire, fighting in brutal colonial wars and surviving multiple death sentences while hiding a biological secret that would eventually stun the Vatican.
A Daring Escape from the Cloister
Born into a noble Basque family in 1585 or 1592, Catalina de Erauso was placed in a Dominican convent in San Sebastián at the age of four. Her parents intended for her to remain there for life. However, at age fifteen, following a violent physical altercation with a senior nun, she stole the convent keys and fled into the night.
Hiding in a grove of chestnut trees, she cut her hair short and skillfully tailored her religious habit into a tunic and breeches. Adopting a male identity, she traveled across Spain unnoticed. Eventually, she secured a job as a ship’s boy on a vessel bound for the New World. The captain of the ship was her own uncle, who failed to recognize his niece in her new guise.
War and a Fratricidal Duel
Upon arriving in South America, Antonio—as he was now known—enlisted in the Spanish colonial army. He was deployed to the front lines of the Arauco War in present-day Chile. He quickly developed a reputation for ruthlessness in battle and skill with a blade, earning a promotion to Alférez (Lieutenant). However, his violence extended into his personal life.
He was frequently involved in gambling disputes and street brawls. During a duel in the pitch-black streets of Concepción, Antonio fatally stabbed his opponent. As the man lay dying, he spoke, and Antonio realized with horror that he had just killed his own brother, Miguel, who had traveled to the Americas separately.
The Papal Dispensation
After years of fleeing the law for various crimes, Antonio was cornered in Peru in 1623 and faced execution. In a final bid to save his life, he demanded an audience with Bishop Agustín de Carvajal. He confessed that he was biologically female and a former nun.
A subsequent examination by a panel of matrons confirmed his biological sex. The revelation shocked the Spanish Empire, but instead of punishment, he received fame. Antonio traveled to Rome to meet Pope Urban VIII. The Pope granted him special permission to continue wearing men’s clothing and to live publicly as a man.
A Quiet End in Mexico
Armed with this papal authorization, Antonio returned to the Americas, settling in New Spain (modern-day Mexico). He retired from military service and established a business as a muleteer, transporting silver and goods along the dangerous roads between Veracruz and Mexico City.
He lived the remainder of his life as a man, known to locals as the “Lieutenant Nun.” In 1650, while guiding a shipment near Orizaba, he died suddenly. His autobiography remains the primary record of his decades-long deception.
In the 1600s, a 15-year-old novice fled a Spanish convent, cut her hair, and sewed men's clothes from her habit.
She vanished onto a ship to the Americas.
This wasn't just an escape.
It was the birth of Antonio de Erauso, the "Lieutenant Nun" who fooled an empire…🧵👇 pic.twitter.com/EDgMA81Rd4
— Fascinating True Stories (@FascinatingTrue) December 15, 2025