(Edited for modern English, with minor abridgement.) She was born Teresa Sanchez de Cepeda y Ahumada, in 1515, during Spain's Golden Age of discovery and conquest. But St. Teresa of Avila committed to a different--and greater--two-fold success: discovery of a soul's ecstatic union with God; and conquest of the worldly entanglements that jeopardize that unfathomable relationship. From her earliest years, Teresa knew her life would be offered to God. So, at seven years of age, the little saint and her brother tried to run away from home, seeking to spread Christianity, and risk martyrdom, in the land of the Moors. That spiritual dedication was never lost. In later years, fighting spiritual laxity, she reinvigorated her Carmelite Order, while establishing dozens of devout monasteries in Spain. She was known to miraculously levitate in ecstasy and to fast, seemingly, beyond the limits of human nature. She is most remembered, however, for her writings, which offer an unparalleled glimpse into the power of prayer and the sublime mysteries of Divine consolations. For these inspiring works, she was named Doctor of the Church. The Interior Castle is among her most popular writings because it offers a road map for a journey like no other: an expedition into the uncharted territories of the soul that seeks, in this life, union with God."
Teresa of Avila Kenneth E Nowell, Benedictines of Stanbrook, Paperback, ISBN 10: 0997596023, ISBN 13: 9780997596021