Simon de Montfort and Henry III’s Failed Invasion of France (1242): The Capetian Victory at Taillebourg and Saintes

Simon de Montfort, a French noble by birth, went to England in 1229 to claim family lands and the earldom of Leicester. By 1238, he had joined the court of Henry III and strengthened his position by marrying Eleanor of England, the king’s sister.

When Henry III invaded France in 1242, de Montfort joined the campaign, despite his past conflicts and reconciliations with Henry. However, the campaign ended in disaster for the English, as Louis IX decisively defeated them at the Battles of Taillebourg and Saintes, securing Capetian dominance over Poitou.

Henry III’s Attempt to Reclaim Poitou

• Henry III allied with rebellious vassals in southern France, hoping to restore Plantagenet influence in Poitou.
• His invasion was poorly coordinated, facing the well-organized and disciplined forces of Louis IX of France.
• Simon de Montfort accompanied Henry, despite their prior disputes.

The French Victory at Taillebourg and Saintes (July 1242)

• Louis IX met Henry III’s army at Taillebourg on July 21, 1242.
• The French forces, better prepared and numerically superior, overwhelmed the English and their allies.
• After a crushing defeat, Henry retreated to Saintes, but Louis pursued him, forcing a final confrontation.
• The Battle of Saintes (July 24–26, 1242) further demoralized Henry’s Poitevin allies, leading to their collapse.

Aftermath: Henry III’s Retreat and Truce at Bordeaux

• Henry III, realizing the war was lost, was forced to seek a truce.
• In Bordeaux, a peace agreement was arranged, effectively ending Plantagenet ambitions in Poitou.
• The southern French lords abandoned their rebellion, leaving Louis IX’s authority unchallenged in the region.

Impact on Simon de Montfort

• The failed campaign further strained de Montfort’s relationship with Henry III.
• De Montfort would later turn against the king, becoming a leader of the English baronial opposition and a key figure in the Second Barons’ War (1264–1267).

The French victories at Taillebourg and Saintes in 1242 were a decisive moment in the Capetian-Plantagenet struggle, securing Capetian control over western France and further weakening English claims on the Continent.