Saint 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 during the Counter-Reformation. Teresa founded several convents, emphasizing a return to a more contemplative and austere lifestyle. Her most famous works include The Interior Castle and The Way of Perfection, which explore the journey of the soul towards God. In 1970, she became the first woman to be declared a Doctor of the Church, recognizing her significant contributions to Christian spirituality and theology.