England’s relations with France from 1399 to 1415 were shaped by contested dynastic claims, domestic insecurity, and political ambitions, culminating in Henry V’s preparations for war.

Causes of the Renewal of War with France

The Lancastrian Claim and Dynastic Tensions

When Henry IV usurped Richard II in 1399, his legitimacy was questioned both at home and abroad. The French royal court, influenced by the powerful Duke of Orléans and Queen Isabeau, refused to recognise Henry’s seizure of the throne. Instead, they offered asylum to Richard’s supporters and maintained a claim to the English crown on behalf of the young Edmund Mortimer, Earl of March, who had a strong hereditary right. This refusal of recognition worsened Anglo-French relations and created an unstable backdrop for renewed conflict.

French Civil War: Armagnacs and Burgundians

France during this period was divided by the bitter rivalry between the Armagnac and Burgundian factions. Henry IV and later Henry V exploited these divisions to strengthen England’s diplomatic hand. The instability of France offered opportunities for England to intervene, particularly as French nobles were distracted by internal conflict, leaving room for English pressure in contested territories like Aquitaine.

Economic and Territorial Pressures

The legacy of the Hundred Years’ War continued to weigh heavily on both kingdoms. England still possessed lands in Gascony, but their defence required continual resources. Trade routes across the Channel, especially involving the lucrative wine trade, were threatened by piracy and French raids. This economic dimension pushed the English crown to consider renewed campaigns to secure territorial claims and stabilise finances.

The Role of Honour and Chivalry

Richard II’s downfall had tarnished England’s international standing, and Henry IV’s troubled reign failed to restore it. The chivalric culture of the late Middle Ages valued military prowess and victories as a way to establish legitimacy. Thus, pursuing war in France was not only strategic but also a means to enhance the prestige of the Lancastrian dynasty.

Early Diplomatic Relations under Henry IV (1399–1413)

Initial Caution and Internal Challenges

Henry IV inherited a fragile crown, beset by revolts such as the Percy Rebellion (1403) and the prolonged Glyndŵr Rising (1400–1415) in Wales. These crises limited his capacity for foreign war. Consequently, Henry’s diplomacy with France was defensive and cautious rather than aggressive, aimed at buying time to consolidate his throne.

Marriage Negotiations

Diplomacy often took the form of proposed royal marriages. Henry IV sought to secure his dynasty through matrimonial alliances, at times considering unions between his children and French royalty. However, the French court’s refusal to acknowledge his kingship meant such negotiations rarely progressed, reinforcing diplomatic stalemate.

Naval Clashes and Piracy

Despite attempts at negotiation, Anglo-French relations were marked by persistent conflict at sea. English and French privateers raided shipping across the Channel, undermining trade and escalating hostility. These clashes were not full-scale war but illustrated the fragility of peace.

The persistent presence of privateers blurred the line between war and peace, maintaining low-level tension throughout Henry IV’s reign.

Relations with Burgundy and Orléans

Henry IV cautiously cultivated links with the Burgundian faction, whose rivalry with the Armagnacs gave England a potential ally inside France. However, his domestic difficulties prevented a deeper commitment, meaning opportunities to exploit French divisions were postponed until Henry V’s reign.

Transition to Henry V and Renewed Aggression (1413–1415)

Restoration of Order and Prestige

When Henry V ascended the throne in 1413, he inherited a realm weary of rebellion but yearning for stability. His firm governance and personal charisma quickly restored royal authority, allowing him to consider more ambitious foreign policies.

Revival of War Aims

Henry V emphasised England’s traditional claims to the French crown and the duchy of Normandy.

The royal arms used from Henry IV (adopted 1406) through the 15th century, quartering England with France modern. This heraldic union symbolised England’s claim to the French throne, central to renewed conflict. Source
These claims had lain dormant under Henry IV but were revived to justify a new phase of the Hundred Years’ War. By invoking legal and dynastic rights, Henry presented his actions as legitimate rather than opportunistic.

The use of this long-running conflict as a framework legitimised Henry’s aggressive posture in the years preceding 1415.

Diplomacy and Demands

Between 1413 and 1415, Henry V opened negotiations with the French court, demanding the restoration of territories in Normandy, Anjou, and Aquitaine, alongside recognition of his claim to the French crown.

A colour-coded map of France showing English holdings in Normandy and Guienne–Gascony (Aquitaine). It anchors England’s territorial demands in diplomacy up to 1415. Note: it also marks Burgundian possessions from 1435, which exceed this topic’s timeframe. Source
These demands were deliberately excessive, serving as both a negotiating tactic and a justification for war when France rejected them.

Exploiting French Divisions

Henry V’s diplomacy was skilful, as he cultivated relations with the Duke of Burgundy, who had murdered the Duke of Orléans in 1407 and sought allies against the Armagnacs.

A 19th-century engraving by Alphonse de Neuville depicting the 1407 assassination of Louis of Orléans in Paris. The murder deepened the Armagnac–Burgundian civil war, a division Henry V later leveraged diplomatically. Source

This strategy ensured that when war resumed, France’s internal divisions would hinder its ability to resist England effectively.

Towards the 1415 Campaign

By 1415, Henry V had consolidated his domestic position, secured parliamentary funding, and framed his military ambitions as a rightful pursuit of justice and inheritance. The combination of dynastic claims, economic pressures, and opportunistic diplomacy set the stage for the invasion of France and the famous Battle of Agincourt later that year.