When Louis IX became king of France he was too young to rule. His mother, Blanche of Castile, ruled France on his behalf.

At just twelve years old, upon the death of his father, Louis IX became king of France. Because Louis was too young to rule, France was governed by the queen-mother Blanche of Castile, the widow of Louis VIII. The English believed the time was right to regain lost ground in Normandy, but it would be several years before any expeditions would take place. ¹

Louis IX, being twenty-one years old, had the authority to rule France unaided. His mother, Blance of Castile, who had been acting as regent since the death of Louis VIII, still had influence over her son.

With the fall of Jerusalem and the crushing defeat of the Christian armies at Gaza, Louis IX of France took the cross and prepared for a Crusade. It took him four years to set sail. ¹

After the Christians were defeated at Gaza in 1244, King Louis IX of France took the cross. He only managed to set sail for Cyprus some four years later, landing at Damietta in June of 1249, Louis had to wait until the Nile floods had reduced before continuing for Cairo. Held up and cut off from Damietta, the French King's camp was struck with disease and most of his men were killed or captured. Louis was taken prisoner and had to pay a ransom to be freed. ¹

While her son, Louis IX of France, was away taking part in the Crusades Blance of Castile ruled France. She did so until her death in 1252. ¹

The Treaty of Corbeil was a treaty between Louis IX of France and James I of Aragon. Both sides gave up ownership of certain lands in exchange for peace.  ¹

The Treaty of Paris also known as the treaty of Albeville/Abbeville was a treaty between Louis IX of France and King Henry III of England in which Henry agreed to the loss of Normandy, Maine, Anjou and Poitou. These areas had been lost under the reign of King John. Henry was able to keep the lands of Gascony and parts of Aquitaine. This won Henry the support of Louis IX of France against the rebellious Barons back in England.

King Louis IX of France held a court at Amiens known as the Mise of Amiens to decide if King Henry III of England should be freed from the obligations forced upon him by the Provisions of Oxford in 1258 by the Barons. Louis agreed that Henry should be freed and ruled against the Barons.

King Louis IX of France once again set out on Crusade, not to the east but towards Tunis. Charles, the brother of Louis, influenced the direction as Charles had plans in the East. At Cathage in July, the plague broke out and in August Louis died. ¹

Pope Boniface VIII made King Louis IX of France a saint of the Church twenty-seven years after his death whilst on crusade in the Holy Land. ¹