'Caxton's Ovid' is a Middle English translation by William Caxton, which he completed in 1480, of a Middle French version of the 'Ovide moralisé en prose II'. This edition presents Book I of the two texts in parallel. 'Caxton's Ovid' and the 'Ovide moralisé en prose II' derive from a wider group of allegorized versions of Ovid's 'Metamorphoses' and represent a synthesis of classical and Christian learning. This edition shows one way in which the Middle Ages accommodated Ovid's 'Metamorphoses': here it is presented as an encyclopaedic compendium in which classical mythology, which combines Ovid's transformation myths with myths from other sources, is enriched with Christian learning, biblical episodes, and other encyclopaedic details. The introduction addresses the question of Caxton as translator, and the edited texts are followed by a commentary and glossary. The volume is the first in a series designed to edit the whole of 'Caxton's Ovid'.