Juan de Leví is documented in a contract of 1403 for an altarpiece at Montalban as being in the process of executing a retable 'of the story of Saint Catherine' for Fernardo Pérez Cavillo, Bishop of Tarazona in Aragon. Post was at first reluctant to accept the identification of that picture with a retable of Saints Lawrence, Prudentius and Catherine still in a chapel of the ambulatory of the cathedral there (op.cit., III, 1930, pp.186-190); he subsequently changed his mind, however, expanding the artist's oeuvre in later volumes (ibid., IV, 1933, Part II, pp.626-30; VIII, 1941, Part II, pp.658-60, and loc.cit.) and describing him as a 'charming exponent of the early stages of the international movement in Aragon'