This is the first biography of Eileen Egan (d. 1912-2000), one of the great unsung heroes of the Catholic peace movement. She worked for Catholic Relief Services after the war. Met Mother Teresa in 1955 and became her close friend, traveling partner (and biographer). Her association with Dorothy Day began in the 1940s. She was a founder of Pax Christi. Lobbied the bishops at Vatican II to condemn nuclear weapons. Advised the US bishops on their pastoral on peace. As an NGO delegate pressed UN to recognize conscientious objection.