France is less a fixed enemy than a changing horizon of threat, alliance, and ambition. For Arthur, it is one danger against which a future English ruler must prepare; for Catalina and her family, it belongs to a Spanish program of expansion; and for Henry VIII, war against it offers a stage on which to prove kingship. Yet the campaigns shaped around France repeatedly reveal that dynastic partners pursue their own interests, and that military glory depends on practical preparation as much as on royal desire.

A frontier in Arthur’s plans

Arthur and Catalina understand peace as the condition that could allow a recently bloodied kingdom to flourish. Arthur believes the old rivalry between Yorkists and Lancastrians has ended with him, but sees the northern border as requiring constant protection. His proposed defenses also face south: he wants a chain of castles and beacons against France and the Moors, so that an attack on the coast could be reported inland and London warned. The plan treats France not as a distant abstraction but as one possible direction from which danger might travel, demanding warning systems and fortifications rather than confidence in a single victory.

Their imagined rule is broader than defense. Catalina expects an alliance between the English and Spanish crowns to bring strength and influence across Europe. Her account of her father’s ambitions places France within a projected Spanish expansion: after Castile, Aragon, and Granada, Ferdinand of Aragon has his sights on Navarre, Naples, and regions of southern and western France. In her vision, the partnership between England and the Spanish royal family could become powerful enough to divide France and reshape Europe. France thus appears both as a territory coveted by a neighboring monarchy and as the obstacle around which a grand alliance might be organized.

From enemy to unexpected partner

The political map changes when Catalina learns that her father has allied with Louis XII of France. She is astonished: she had imagined the two rulers as lifelong enemies and had understood their rivalry as fundamental. The alliance is presented as a practical arrangement to invade Italy and share the spoils, not as a crusade. That contrast unsettles Catalina’s expectations. A king may abandon old enmities when political advantage changes, while the language of religious war does not explain every campaign.

The prospect of war with France also divides the English court. When Henry VIII speaks of taking the kingdom to war, Margaret Beaufort objects that there is no English quarrel with France and warns against fighting merely to serve Catalina’s father. Henry answers that the French king is a danger and invokes the glory of England. Catalina intervenes diplomatically, softening the exchange rather than openly escalating it. Her position is complicated: she is proud to represent her country of birth at the English court, but she must also manage the consequences of Spanish policy for her husband’s kingdom.

Henry’s appetite for war grows despite the caution of his father’s advisers. He sees warfare as proof that he has inherited the throne, while eager young courtiers encourage his ambitions and a long history of hostility makes peace with France seem unnatural to them. The French ambassador encounters Henry’s anger at their first meeting, when Henry denies having sent a peaceable letter prepared by the council. Katherine of Aragon ensures she is present at their next meeting and prompts Henry to greet the ambassador pleasantly. France therefore becomes a test not only of foreign policy but of the new king’s temperament—and of Katherine’s ability to temper it.

Campaigns, supply, and divided purposes

In 1512, England sends a fleet to join Ferdinand of Aragon’s campaign against the French. Henry is eager to take part, but Katherine of Aragon concentrates on the material conditions of war: provisioning ships, stocking armories, and equipping soldiers. She has learned from watching her mother support campaigns that a battle can be won only when the army is reliably supplied. The expedition leaves in fine array, and Katherine expects the alliance to defend the Pope, defeat France, and recover English lands there. That confidence rests on Ferdinand’s assurances that victory will be quick and profitable.

The operation instead exposes the cost of depending on an ally whose plans are concealed. English troops wait at Fuenterrabia without being committed to battle. Ferdinand uses their presence to hold French forces in a defensive posture while he marches into Navarre. Katherine recognizes from the idle camp and the commanders’ reports that the English are serving as a diversion, not as partners in the promised campaign. The army returns in December in disgrace: orders and reinforcements have not arrived, mutiny has broken out among hungry and weary troops, and two thousand men have died of illness. The failure is not simply a reversal on the battlefield; it is the consequence of strategic deception and neglect of the force’s needs.

The next year brings another plan. England is to invade Normandy while Ferdinand attacks Guienne and Maximilian I, Holy Roman Emperor, joins the northern campaign. Katherine has Thomas Wolsey ask towns across the kingdom how many men they can muster. At the same time, Ferdinand is negotiating peace with France. He later blames the breakdown in communication on his ambassador and letters going astray. Katherine understands that her father has chosen Spain’s safety over the alliance’s promises, and accepts that he may join the English once victory appears likely. For her immediate purposes, the projected French campaign also gives Henry a war of his own while she turns to the Scottish threat.

France as the measure of ambition

France remains the desired theater of Henry’s military reputation. When Edward Howard’s success against Scottish privateers makes the king envious, Katherine redirects his attention toward a European campaign against France, in alliance with the leading rulers of Christendom. Henry’s childhood admiration for Crécy and Agincourt makes the appeal of that prospect especially strong. Yet Katherine’s own confidence is inseparable from her experience of actual campaigning: she organizes the fleet and army, but the first expedition teaches her that an ally’s strategic priorities can overturn even meticulous preparation.

The French war also fails to follow the heroic script Henry expects. English knights reach Cádiz for a crusade that never sails, while the political situation changes again: Katherine translates letters reporting that the Pope and France are at war, and that Louis XII has challenged the Pope’s authority. The shifting conflict makes clear that alliances and enemies are not permanent categories. France can be a feared adversary, an ally of Spain, the target of an English invasion, and a participant in a struggle with the Pope within a short span of the narrative.

By the time Henry prepares to sail for Calais in 1513, the French campaign carries both spectacle and danger. The first troops have already been sent; after Edward Howard’s death, Katherine works harder to ensure that weapons and equipment are dependable. Henry’s encounter with the death of a brilliant young courtier makes war less like a story or a joust and more like a real undertaking with irreversible consequences. France gives the king the stage on which he seeks glory, but the novel’s repeated reversals—failed coordination, illness, deception, and death—make it equally a measure of how little royal ambition can control the realities of war.