Saint Teresa, also known as Saint Teresa of Ávila, was a prominent Spanish mystic and reformer of the Carmelite Order. Born in 1515, she dedicated her life to prayer and the spiritual development of others. She is best known for her writings on prayer and contemplation, which have influenced Christian spirituality. In 1970, she was declared a Doctor of the Church, making her one of the first women to receive this honor. Her most famous works include The Interior Castle and The Way of Perfection, which explore the journey of the soul towards God. Saint Teresa passed away in 1582, and her feast day is celebrated on October 15.