This book offers the first scholarly edition of Pour ce que plusieurs, a French treatise on the legal debates that underpinned the Hundred Years War. It was written in 1464, perhaps by Guillaume Cousinot II, and survives in twenty manuscripts; it was also printed at least eleven times by 1558, most commonly under the title La Loy Salicque, première loy des françois. One of those books fell into the hands of an anonymous English customs official, perhaps from Ipswich, who composed an extremely detailed reply which he called A declaracion of the trew and dewe title of Henry VIII. This work did not enjoy the same success, surviving in just two autograph manuscripts, together with a seventeenth-century transcription of the presentation copy. As a result, this unique and important treatise has received no attention from historians.