Saint Catherine Disputing and Two Donors. c 1380 Cenni di Francesco di Ser Cenni. A princess of great learning and beauty, St Catherine of Alexandria (c. 4th) was challenged to a debate with fifty pagan orators, all of whom she converted to Christianity. Here she counts off the points of her dispute to two men who wear haloes as an indication of their conversion by her arguments. Two diminutive donors wearing the habits of Franciscan tertiaries kneel at the left.