Teresa de Ávila, also known as Saint Teresa of Jesus, was a prominent Spanish mystic, Roman Catholic saint, and influential author of the Counter-Reformation period. Born on March 28, 1515, in Ávila, Spain, she entered the Carmelite convent at a young age, eventually reforming the order to establish the Discalced Carmelites alongside John of the Cross. Her seminal literary contributions, "The Interior Castle" and "The Way of Perfection," explore profound spiritual themes and mystical theology, emphasizing personal prayer and the soul's journey toward divine union. Canonized in 1622, Teresa remains a celebrated figure in Christian mysticism and a Doctor of the Church.