Dual monarchy of England and France

The dual monarchy of England and France, a pivotal yet ultimately unsustainable political arrangement, emerged from the tumultuous final decades of the Hundred Years' War. Its formal inception dates to October 21, 1422, following the death of Charles VI of France. Charles VI, influenced by factional strife and perhaps his own declining mental state, had signed the Treaty of Troyes in 1420.

This treaty disinherited his son, the Dauphin Charles (later Charles VII), and designated Henry V of England as his successor and regent, with Henry's heirs to inherit the French crown. This act was a profound contravention of Salic Law, the traditional French law of succession which prohibited the alienation of the crown and succession through the female line.

Henry V's ambition was to unite the two kingdoms permanently under English rule, a goal that seemed within reach due to English military successes. Upon Henry V's death in 1422, his infant son, Henry VI, inherited claims to both thrones. Henry VI was crowned King of England in 1429 and King of France in Paris in 1431, styled as Henry II of France.

However, his sovereignty was largely confined to English-occupied territories in northern France, administered by a regency council. The Dauphin Charles, meanwhile, maintained control over the southern regions, establishing a rival court and government, setting the stage for a protracted struggle for legitimacy and control.

The dual monarchy's precarious existence was significantly challenged by the emergence of Joan of Arc. This remarkable figure, claiming divine inspiration, galvanized French national sentiment and provided a crucial impetus for the Dauphin's cause. Her leadership and strategic influence were instrumental in lifting the Siege of Orléans in 1429, a pivotal victory that reversed English fortunes.

This military success paved the way for the Dauphin's coronation at Reims on July 17, 1429, a ceremony that dramatically bolstered his legitimacy in the eyes of the French populace and solidified his claim as Charles VII.

The political landscape shifted dramatically in 1435 with the Treaty of Arras. This accord saw the powerful Duke of Burgundy, Philip the Good, abandon his alliance with the English and reconcile with Charles VII. Burgundy's defection was a devastating blow to the dual monarchy, depriving Henry VI of a critical ally and significantly weakening English military and political leverage.

This marked a turning point, signaling the decline of English influence and the ascendance of French national unity under Charles VII.

Following the Treaty of Arras and the coronation of Charles VII, French military efforts intensified. Charles VII implemented significant military reforms, including the creation of a standing army and improved artillery, which proved highly effective against the increasingly overstretched English forces. The French gradually reconquered lost territories, systematically dismantling the English presence in France.

The culmination of this protracted conflict arrived in 1453. The decisive French victory at the Battle of Castillon on July 17, 1453, effectively ended major English military operations in France. This was swiftly followed by the French capture of Bordeaux on October 19, 1453.

This final conquest expelled the English from all their continental possessions, with the sole exception of the strategic port of Calais. The fall of Bordeaux marked the definitive end of the dual monarchy and the Hundred Years' War, confirming Charles VII as the undisputed sovereign of nearly all of France and ushering in a new era of French consolidation and national identity.

The dual monarchy represents a fascinating, albeit ultimately failed, attempt at dynastic union driven by English ambition during a period of French internal division. Its legacy is complex, highlighting the resilience of French national identity and the limitations of military conquest in achieving lasting political integration. The period underscores the critical role of legitimacy, popular support, and shifting geopolitical alliances in shaping medieval state formation.

Historiographically, the dual monarchy is often viewed as a critical juncture in the development of both English and French nationhood. For England, its failure marked a turning point, leading to internal conflict (the Wars of the Roses) and a reorientation towards insular concerns. For France, the successful expulsion of the English and the consolidation of royal power under Charles VII laid the groundwork for the emergence of a powerful, centralized state in the early modern period.

The episode serves as a potent reminder of how dynastic claims, however legally constructed, often clash with the emergent forces of national consciousness and self-determination.