San Juan de la Cruz (Ávila, 1542 - 1591) was a Carmelite friar. He studied philosophy at the University of Salamanca. He cooperated with Saint Teresa of Avila in the reformation of the Carmelite order. In 1577, following his refusal to relocate after his superior's orders, he was jailed in Toledo, and later freed.
His two most important poems are:
The Spiritual Canticle, an eclogue in which the bride (representing the soul) searches for the bridegroom (representing Jesus Christ).
The Dark Night of the Soul, that narrates the journey of the soul from her bodily home to her union with God.
He also wrote three treatises on mystical theology and the Ascent of Mount Carmel, a more systematic study of the ascetical effort of a soul looking for perfect union with God.