Rupert Mayer was a German Jesuit priest and theologian who became a prominent figure of Catholic resistance against the Nazi regime in Munich. Born in Stuttgart in 1876, he joined the Society of Jesus in 1900 following his ordination. During the First World War, he served as an army chaplain and earned the Iron Cross for his bravery, though he lost his left leg during a grenade attack. He spent his later years defending the faith against political persecution, which eventually led to his imprisonment.