Answer:
Santa Teresa of Avila was a Carmelite, mystical and Holy Catholic nun of the sixteenth century, important for her works on the contemplative and spiritual life and for her performance during the Counter Reformation. She was also one of the reformers of the Carmelite Order and is considered co-founder of the Order of the Discalced Carmelites along with St. John of the Cross.
In 1622, forty years after her death, she was canonized by Pope Gregory XV. On September 27, 1970, Paul VI proclaimed her a Doctor of the Church and recognized her title of Mater Spiritualium (Mother of Spirituality), because of the contribution that the saint gave to Catholic spirituality. Her books, including an autobiography and her masterpiece, "The Inner Castle", are an integral part of Spanish Renaissance literature and the corpus of Christian mysticism. Her meditative practices are detailed in another important work, the "Path of Perfection".
After her death, the cult of Santa Teresa spread throughout Spain during the 1620s, mainly during the national debate over the choice of a patron saint along with Santiago Matamoros.