John of Jesus Mary was born in the town of Calahorra in Spain on January 27, 1564 to Diego de San Pedro and Anna De Ustarroz.
At the university of Alcalà de Henares, together with studies in philosophy and theology he specialized in Latin and Greek, becoming an elegant Latinist, an excellent dialectician in school controversies as well as an expert in the Hebrew language.
In 1582, he entered the Discalced Carmelite novitiate in Pastrana, taking the name of John of Jesus Mary and on January 23, 1583 he made his profession. In 1584 he was sent to Italy in the newly established community of Genoa; here he was ordained a priest in 1590. First in Genoa, then in Rome, he was master of novices, a position that marked the ministry of his whole life. In 1584 he was sent to Rome as Master of novices and in 1597 he was commissioned to revise the constitutions and laws of the Order, after Clement VIII had made the Italian branch independent of the Spanish one.
In the General Chapter of 1605, John of Jesus Mary was elected General Counsellor and Master of novices. In that of 1608, he was elected Procurator General of the Order. In this office he carried out the cause of canonization of Mother Teresa of Jesus, of whom he was one of the first biographers.
In the General Chapter of 1611, celebrated in Montecompatri, John of Jesus Mary was elected Superior General. During his generalate the "Mission Seminary" was established, first at the small Church of Saint Paul in the Sallustian gardens of Rome (today Santa Maria della Vittoria), later transferred to the Basilica of St Pancrazio outside the walls. Thanks to the fruits of this Seminary, the Discalced Carmelites were able to open houses in Ormutz, in the Persian Gulf, in Tatta, at the mouth of the Indus, in Goa, England (1614), Paris, Louvain, Lviv (in 1613, with the aim of helping reconciliation of the Ruthenians with Rome), Cologne, Milan (1622), Bologna.
At the end of his mandate as Superior General and foreseeing that his end was nigh, he chose to retire to the splendid solitude of Montecompatri. There he died on 28th of May, 1615.
On 7th of May 1999, the decree of validity of the Diocesan Inquiry into the "life, virtue and fame for holiness" was granted.
On November 25, 2021, the decree of his heroic virtue was promulgated.
