The unique illustrations and decoration in the Yale Law School copy of the Nova statuta Angliae offer clues for a new assessment of the manuscript’s dating and significance as well as a picture of the intricate mechanisms of the textual cultures involved in the production, use, and interpretation of a single, fifteenth-century law codex. Though Goldman Law Library MS. G. St. 11.1 was made by some of the same scribes and artists who produced standardized copies of the Nova statuta, the manuscript differs from these other copies by echoing iconography associated with King David in five of its six royal portraits, which supports the legitimacy of the Lancastrian kings, especially Henry VI. The change in iconography for the portrait of Edward IV suggests that he compares negatively with his predecessors. This pattern of iconography, as well as the Yale manuscript’s inclusion of the arms of Margaret of Anjou in its border decoration, links the manuscript to Lancastrian polemic, especially the “mirrors for princes” composed by supporters of the Lancastrian party to defend Henry VI and his son Edward of Lancaster from attacks against their right to rule. The Yale manuscript’s closest links are to Sir John Fortescue’s De laudibus legum Angliae, which argues that Prince Edward should have his own copy of the statutes of England for daily study. Taken together, the different types of evidence suggest that the Yale Nova statuta was begun in the late 1450s and intended as a gift for Prince Edward from his parents.