St. Teresa of Avila was born in 1515 at Avila, Spain, and her mother Beatriz was determined to bring her up as a good Christian. She attempted to find martyrdom by running away from home when she was seven, but was promptly stopped by her uncle. She later became a Carmelite nun and began to experience, while suffering from sickness, spiritual ecstasy as a result of reading Francisco de Osuna's Third Spiritual Alphabet. In 1599 she was convinced that she was actually seeing visions of Christ, which continued often for two years.

Teresa of Avila founded a good many convents, including at Andalusia, Palencia and Soria. She is also the author of The Interior Castle, The Way of Perfection, and an Autobiography. She died in 1582 at the age of 67, and was canonized by Pope Gregory XV in 1622. Her feast is celebrated on October 15.