Book excerpt: The Serpent and the Rose examines the theological and liturgical context for the doctrine of the Immaculate Conception in the Middle Ages, from primary sources in Iberian archives. Its main focus is a study of Marian poetry from Alfonso the Wise and Gonzalo de Berceo through to the poetry collections of the late fifteenth century, showing how poets took themes from the Bible and apocryphal literature, combining them to defend and praise Mary’s conception without sin. Individual chapters assess how they depicted Mary’s prefiguration in the Old Testament by the Woman who defeated the serpent, the young bride of the Song of Songs, or the semi-deity, Wisdom, how they portray her as the mystic rose and as the new Eve.