St. John of the Cross stands as one of the most important mystical philosophers in Christian history. He was born at Hontoveros, Old Castile, 24 June, 1542; died at Ubeda, Andalusia, 14 Dec., 1591. The son of poor silk weavers of Toledo, John was born Juan de Yepes y Alvarez in Fontiveros. John's father died when the boy was quite young, leaving his mother, a member of a lower social class, to raise him alone. John was sent to the poor school at Medina del Campo, whither the family had gone to live, and proved an attentive and diligent pupil; but when apprenticed to an artisan, he seemed incapable of learning anything.

Thereupon the governor of the hospital of Medina took him into his service, and for seven years John divided his time between waiting on the poorest of the poor, and frequenting a school established by the Jesuits. He entered the Carmelite Order in 1563, continuing his studies at the University of Salamanca, where he began to teach while still a student. After being ordained in 1567, John met St. Teresa of Avila, another of the great mystics of the Christian tradition.

Following Teresa's lead in attempting to reform his Order, John, in 1568, initiated a very severe form of monasticism in a tiny farmhouse. These monks went so far as to go barefoot, indicating their commitment to poverty, lending to them the appellation of "Discalced" or "shoeless." Over time, a rift arose between the traditional Carmelites and John's Discalced Carmelites, leading in 1576 to John's arrest and imprisonment. During this period of imprisonment, John wrote much of the poetry that would provide his greatest contribution to later generations.

Eventually, the rights of the Discalceds were recognized, and John took on various roles of leadership within the order. After some fifteen years of leadership, he died in 1591, leaving behind a number of remarkable works of Christian mysticism: Ascent of Mount Carmel, Dark Night of the Soul, and the Spiritual Canticle of the Soul.