In August 1568, Juan left Salamanca – where he was finishing his high school studies – to accompany Saint Teresa. Together they founded the convent for women in Valladolid and a few months later, on November 28 of that same year, Juan founded the first convent of the male branch of the Discalced Carmel in Duruelo (Ávila). That day, Juan de San Matías changed his name to Fray Juan de la Cruz.
In 1570 the foundation was moved to Mancera, where Juan served as subprior and master of novices. In 1571 he was appointed rector of the newly founded College of Discalced Carmelites of San Cyril. In 1572, at the request of Mother Teresa, he assumed the position of vicar and confessor of the nuns of the Encarnación convent in Ávila. During his stay there, he accompanies her mother on her foundation trips.
At the General Chapter of the Carmelites in 1575, it was decided to send a visitor of the Order to suppress the reform convents and confine Mother Teresa in a convent. In 1577, Brother Juan de la Cruz was arrested and taken to Toledo. There he is mistreated and isolated for 8 months, during which he was able to write one of his most significant works: the Spiritual Canticle. Providentially, the Discalced Carmel was established as an exempt Province and in 1588 it was recognized as an Order.
After that difficult episode, Saint John of the Cross continued to serve as vicar and made trips to Andalusia (Spain) and to some cities in Portugal until he was summoned to the presence of God in Úbeda, on December 14, 1591. He was canonized by Benedict XIII in 1756 and, since 1952, he has been the patron saint of Spanish-language poets. Saint John of the Cross is part of the list of the 36 Doctors of the Church.