St. Teresa of Avila was a Spanish mystic and reformer of the Carmelite order, born on March 28, 1515. She is known for her deep spiritual writings and her role in the Catholic Church's Counter-Reformation. Teresa emphasized the importance of prayer and contemplation, advocating for a more personal relationship with God. In 1562, she founded the Discalced Carmelites, a reformed branch of the Carmelite order that focused on a simpler, more austere lifestyle. St. Teresa's influential works, such as "The Interior Castle" and "The Way of Perfection," continue to inspire spiritual seekers today. She was canonized in 1614 and declared a Doctor of the Church in 1970.