Edward III's formal assumption on 26 January 1340 of the title of king of France represented surely the most momentous decision of his long and eventful reign. Historians have long recognized that the claim marked a sea- change in Anglo-French relations, transforming the basis on which Edward sought to resolve the long-standing dispute over Plantagenet sovereignty in Aquitaine. Much attention has also been paid to the juristic aspects of the French claim and to its use in English propaganda during the Hundred Years War. The present study aims not to engage directly with the validity of the claim or with the way in which it was deployed in English diplomacy, but to establish how it evolved and was represented in the new royal style (the formal statement of the king's titles) adopted in the wake of the announce- ment of the double monarchy in 1340, and to explore some of the implications of the French royal title for mid-fourteenth-century English domestic politics.

There were two principal and overlapping ways in which the royal style was officially articulated in later medieval England. First, there was the heraldic representation of monarchy found in the royal coat of arms. This visual statement of the king's claims was found in many different media, whether painted on banners, boards and walls, embroidered on cloth, engraved on gold and silver plate, or cast in the matrices of royal seals and coins. Recently, both Michael Michael and Adrian Ailes have worked on the significance of the new quartered arms of France and England adopted in 1340. They have shown that Edward's French mother Queen Isabelle, and possibly Edward himself, had already quartered the leopards of England with the fleurs de lis of France before that date, but had always given formal precedence to England by placing the leopards in what we read as the left- hand side of the upper level of the quartering (read heraldically, from the reverse, as the dexter) and subordinating the fleurs de lis to the right (the sinister). When Edward assumed the French royal title, however, he immediately altered this order of precedence, putting France in the dexter and England in the sinister. This symbolic ordering of the two monarchies within the royal arms remained unchanged for the rest of the reign, even during the period when Edward ceased to exercise the French title between 1360 and 1369.