Catherine of Siena
She wrote a book called Dialogue, which taught that if you love your neighbors it is loving God. She also devoted her life to improving the Catholic church, helping the ill, poor, and spiritually underprivileged. Catherine persuaded the pope to return from Avignon, France and back into Rome. She also tried to start a new Crusade to the holy land, Jerusalem. She died of “holy anorexia”, as she ate very little in the name of God. She became a saint in 1461, and was later made a Doctor of the Church in 1970 by Pope Paul VI and a patron of  Europe in 1999.