Teresa Sánchez de Cepeda y Ahumada was born in 1515 in Ávila, Spain. Her paternal grandfather, Juan Sánchez de Toledo, was a marrano or Converso, a Jew forced to convert to Christianity or emigrate. When Teresa’s father was a child, Juan was condemned by the Spanish Inquisition for allegedly returning to the Jewish faith, but he was later able to assume a Catholic identity. Her father, Alonso Sánchez de Cepeda, was a successful wool merchant and one of the wealthiest men in Ávila. He bought a knighthood and assimilated successfully into Christian society.

After completing her education, she initially resisted the idea of a religious vocation, but after a stay with her uncle and other relatives, she relented. In 1536, aged 20, much to the disappointment of her pious and austere father, she decided to enter the local easy-going Carmelite Convent of the Incarnation, significantly built on top of land that had been used previously as a burial ground for Jews. She took up religious reading on contemplative prayer, especially Osuna’s Third Spiritual Alphabet (1527). Her zeal for mortification caused her to become ill again and she spent almost a year in bed, causing huge worry to her community and family. She nearly died but she recovered, attributing her recovery to the miraculous intercession of St. Joseph. She began to experience instances of religious ecstasy.

Around 1556, friends suggested that her newfound knowledge was diabolical, not divine. She had begun to inflict mortifications of the flesh upon herself. But her confessor, the Jesuit Francis Borgia, reassured her of the divine inspiration of her thoughts. On St. Peter’s Day in 1559, Teresa became firmly convinced that Jesus Christ presented Himself to her in bodily form, though invisible. These visions lasted almost uninterrupted for more than two years. In another vision, a seraph drove the fiery point of a golden lance repeatedly through her heart, causing an ineffable spiritual and bodily pain:

The incentive to take the practical steps inspired by her inward motivation was supported by the Franciscan priest, Peter of Alcantara, who met her early in 1560 and became her spiritual adviser. She resolved to found a “reformed” Carmelite convent, correcting the laxity which she had found at the Incarnation convent and elsewhere besides. Guimara de Ulloa, a woman of wealth and a friend, supplied the funds for the project.

The abject poverty of the new convent, established in 1562 and named St. Joseph’s (San José), at first caused a scandal among the citizens and authorities of Ávila, and the small house with its chapel was in peril of suppression. However, powerful patrons, including the local bishop, coupled with the impression of well ordered subsistence and purpose, turned animosity into approval.

In March 1563, after Teresa had moved to the new convent house, she received papal sanction for her primary principles of absolute poverty and renunciation of ownership of property, which she proceeded to formulate into a “constitution”. Her plan was the revival of the earlier, stricter monastic rules, supplemented by new regulations including the three disciplines of ceremonial flagellation prescribed for the Divine Office every week, and the discalceation of the religious. For the first five years, Teresa remained in seclusion, mostly engaged in prayer and writing.

In 1567, Teresa received a patent from the Carmelite General, Rubeo de Ravenna, to establish further houses of the new order. This process required many visitations and long journeys across nearly all the provinces of Spain. She left a record of the arduous project in her Libro de las Fundaciones. Between 1567 and 1571, reformed convents were established at Medina del Campo, Malagón, Valladolid, Toledo, Pastrana, Salamanca, and Alba de Tormes.

As part of the original patent, Teresa was given permission to set up two houses for men who wished to adopt the reforms. She convinced two Carmelite friars, John of the Cross and Father Anthony of Jesus to help with this. They founded the first monastery of Discalced Carmelite brothers in November 1568 at Duruelo. Another friend of Teresa, Jerónimo Gracián, the Carmelite visitator of the older observance of Andalusia and apostolic commissioner, and later provincial of the Teresian order, gave her powerful support in founding monasteries at Segovia (1571), Beas de Segura (1574), Seville (1575), and Caravaca de la Cruz (Murcia, 1576). Meanwhile, John of the Cross promoted the inner life of the movement through his power as a teacher and preacher.

In 1576, unreformed members of the Carmelite order began to persecute Teresa, her supporters and her reforms. Following a number of resolutions adopted at the general chapter at Piacenza, the governing body of the order forbade all further founding of reformed convents. The general chapter instructed her to go into “voluntary” retirement at one of her institutions. She obeyed and chose St. Joseph’s at Toledo. Meanwhile, her friends and associates were subjected to further attacks.

Several years later, her appeals by letter to King Philip II of Spain secured relief. As a result, in 1579, the cases before the inquisition against her, Father Gracian and others, were dropped. This allowed the reform to resume. An edict from Pope Gregory XIII allowed the appointment of a special provincial for the newer branch of the Carmelite religious, and a royal decree created a “protective” board of four assessors for the reform.

Her final illness overtook her on one of her journeys from Burgos to Alba de Tormes. She died in 1582, just as Catholic Europe was making the switch from the Julian to the Gregorian calendar, which required the excision of the dates of 5–14 October from the calendar. She died either before midnight of 4 October or early in the morning of 15 October, which is celebrated as her feast day. According to the liturgical calendar then in use, she died on the 15th in any case. Her last words were: “My Lord, it is time to move on. Well then, may your will be done. O my Lord and my Spouse, the hour that I have longed for has come. It is time to meet one another.”

She was buried at the Convento de la Anunciación in Alba de Tormes. Nine months after her death the coffin was opened and her body was found to be intact but the clothing had rotted. Before the body was re-interred one of her hands was cut off, wrapped in a scarf and sent to Ávila. Father Gracián cut the little finger off the hand and – according to his own account – kept it with him until it was taken by the occupying Ottoman Turks, from whom he had to redeem it with a few rings and 20 reales. The body was exhumed again on 25 November 1585 to be moved to Ávila and found to be incorrupt. An arm was removed and left in Alba de Tormes at the nuns’ request, to compensate for losing the main relic of Teresa, but the rest of the body was reburied in the Discalced Carmelite chapter house in Ávila. The removal was done without the approval of the Duke of Alba de Tormes and he brought the body back in 1586, with Pope Sixtus V ordering that it remain in Alba de Tormes on pain of excommunication. A grander tomb on the original site was raised in 1598 and the body was moved to a new chapel in 1616.

In 1622, forty years after her death, she was canonized by Pope Gregory XV. The Cortes exalted her to patroness of Spain in 1627. The University of Salamanca had granted her the title Doctor ecclesiae (Latin for “Doctor of the Church”) with a diploma in her lifetime but that title is distinct from the papal honour of Doctor of the Church, which is always conferred posthumously. The latter was finally bestowed upon her by Pope Paul VI on 27 September 1970, along with Saint Catherine of Siena, making them the first women to be awarded the distinction. Teresa is revered as the Doctor of Prayer. The mysticism in her works exerted a formative influence upon many theologians of the following centuries, such as Francis of Sales, Fénelon, and the Port-Royalists. In 1670, her coffin was plated in silver.

In 1626, at the request of Philip IV of Spain, the Castilian parliament elected Teresa “without lacking one vote” as copatron saint of Castile. This status was affirmed by Pope Urban VIII in a brief issued on 21 July 1627 in which he stated: