John of the Cross, † 1591; born in Fontiveros, Spain c. 1542; mystic and poet; ally of St. Teresa of Jesus of Avila in founding the reformed ("Discalced") Carmelite friars [O.C.D.]; suffered imprisonment by the unreformed Carmelites of the Observance; authored The Ascent of Mount Carmel, The Dark Night of the Soul, The Spiritual Canticle, and O Flame of Living Love; known as the "Mystical Doctor"; Discalced Carmelites today number over 4,000 religious.