Born in the Castilian town of Avila in 1515, Teresa entered the Carmelite convent of the Incarnation when she was twenty-one. Tormented by illness, doubts and self-recrimination, she gradually came to recognize the power of prayer and contemplation—her spiritual enlightenment was intensified by many visions and mystical experiences, including the piercing of her heart by a spear of divine love. She went on to found seventeen Carmelite monasteries throughout Spain. Teresa always denied her own saintliness, however, saying in a letter: "There is no suggestion of that nonsense about my supposed sanctity." This frank account is one of the great stories of a religious life and a literary masterpiece—after Don Quixote, it is Spain's most widely read prose classic.