Thomas Aquinas, portrait by Carlo Crivelli, 1476. © Interfoto / Alamy.
St Augustine, fresco by Botticelli, c. 1480. Ognissanti, Florence / photo IAM / akg-images.
John Calvin, c. 1555. Museum Boymans-van Beuningen, Rotterdam / photo akg-images.
Martin Luther, portrait by Lucas Cranach the Elder, c. 1528. Lutherhalle, Wittenberg / photo akg-images.
