Louis IX (French: Louis IX, April 25, 1214 – August 25, 1270) was the eleventh king of the Capetian dynasty in the Kingdom of France (reigned from November 8, 1226 to August 25, 1270). The tenth king of the Capetian dynasty, Louis VIII, and the son of Blanca of Castile. [4]
Louis IX ascended the throne in 1226. In the early days, he devoted himself to suppressing aristocratic rebellions, defeating the joint invasion of rebels and King Henry III of England, successfully strengthening his royal power, and annexing all the British territories in France except for Aquitaine. [12] Afterwards, efforts began to strengthen France's influence along the Mediterranean coast and North Africa. [13] In 1249, Louis IX launched the Seventh Crusade and led his troops to land in Egypt. However, he suffered a disastrous defeat when advancing towards Alexandria and was himself captured by the Egyptian Muslim army. After paying the ransom, he was released and went to Akkah to take over the Kingdom of Jerusalem. In 1254, he returned to France. In 1270, the Eighth Crusade was launched, and he led his army to land in Tunisia, North Africa. Although he once occupied Carthage, he died in August of the same year due to pestis, at the age of 55. [8]
During the reign of Louis IX, judicial, monetary, and military reforms were carried out to strengthen and consolidate centralization, develop culture and art, and bring the Capetian dynasty to its peak. Due to his impartial law enforcement and devout faith, he launched two consecutive Crusades to the East and was posthumously canonized shortly after his death. Later generations referred to him as "Saint Louis" (French: Saint Louis) [4] and referred to his reign as the "Golden Age of Saint Louis" [14]. Since the death of Louis IX, he has been regarded as a model among medieval French and even European monarchs [25-26], and later praised as "a perfect monster that the world has never seen before" 

Juvenile Succession
Louis was born on April 25, 1214, and was the son of Louis VIII, the tenth king of the Capetian dynasty in the Kingdom of France, and Blanche of Castile. [4]
On November 8, 1226, Louis VIII passed away. On the same day, Louis, who was only 11 years old, was crowned on the throne of Reims and inherited the French throne, becoming Louis IX. At the beginning of his reign, he was regent by his mother Empress Blanca. After Louis took office, she continued to assist in politics. When Louis first led the Crusaders to fight in the East, she also served as regent. Blanca was shrewd and capable, and played an important role and influence in Louis's character and governance, as well as in the consolidation and enhancement of the French monarchy. [8]
Flatten internal strife
In France, the unification movement centered around the monarchy and carried out through the continuous expansion of royal territory was a long-term and complex struggle process. Feudal feudal lords regarded ceding territory to claim power as their traditional right. The King of England is nominally a vassal of the King of France and holds large feudal territories in France. Louis IX's grandfather Philip II had incorporated some of the British territories in western and central France into the French royal family's territory, but there were still vast British territories in southwestern France. When Louis IX succeeded to the throne, it was only three years after the death of Philip II. The ambitious French princes and English kings, upon seeing a 12-year-old young master supported by a 38 year old widow from a foreign country, saw it as a rare opportunity to seize power and expand their territories. [8]
When Louis IX was crowned in 1226, many nobles did not participate. Soon, a noble alliance against the royal family was formed, and an open civil war began. In 1228, King Henry III of England participated in the rebellion and landed in Brittany. But the aristocratic alliance itself is lax, and the big nobles have their own plans and different steps. Henry III, due to conflicts with the British nobility, could only operate in France with weak armed forces. Louis IX personally led his troops to the expedition. He ordered the reconstruction of the castle in Angers and advanced towards the base of Henry III, Nantes. Henry withdrew his troops without any success.

In France, the monarchy has a certain degree of prestige, with small and medium-sized nobles leaning towards it, and the Catholic Church generally supporting it; Urban citizens are an important support force for monarchy. In 1227, Blanca and Louis IX were on their way back from Orleans to Paris when the rebellious princes led their armies to gather in Corbel, south of Paris, in an attempt to intercept them. Citizens of Paris and other cities organized teams to go out of the city to protect themselves upon hearing the news. On the road leading to Paris, people gather in groups to pray for the king and prepare for battle to be loyal to him. The feudal lords who participated in the rebellion were intimidated by the prestige of the masses and had to lead troops back. In 1229, 34 cities between the Seine River and Flanders swore allegiance to the king. [8]
On May 27, 1234, 19-year-old Louis IX married 13-year-old Margaret, the eldest daughter of Count Raymond Berengar IV of Provence. [8] On the 28th, Margaret was crowned as the Queen of France. [17]
The advantage of monarchy has been largely established in the years following the beginning of the turmoil. From 1240 to 1243, there was only unrest in the southern part of France. Most of the territory of the Count of Toulouse in southern France was incorporated into royal territory in 1229. But the Catholic Church and royal officials, under the pretext of continuing to suppress Albigist heresy, unjustly persecuted residents, forcibly occupied land, invaded local nobles, and incited resistance and struggle. It was not until early 1243 that southern France finally settled under royal control. However, large areas of land such as Keane and Gascony in southwestern France are still British territories. This was decided in the treaty between the victorious Louis IX and the defeated Henry III. Louis explained this treaty: the kings of England and France were by marriage (Eleanor, the sister of Louis's wife Margaret, was the queen of Henry III), and their children were "first cousins". Therefore, "it is appropriate to maintain peace between us.".

The First Eastern Expedition
Main entry: Seventh Crusade to the East
After the rebellion of the aristocracy was stopped, France was basically in a state of peace, allowing Louis to participate in foreign aggression wars. In order to consolidate France's position in the Mediterranean, he supported his brother Charles of Anjou and occupied southern Italy and Sicily, becoming Charles I of the Anjou dynasty in Naples. [8]
Due to frequent trade between southern French cities and North Africa, he attempted to strengthen France's influence in North Africa through the Crusades. In 1244, the holy land of Jerusalem and the important Syrian city of Damascus were successively occupied by Muslims. If Western countries do not immediately send troops, the Christian kingdoms in the East will quickly collapse. At this time, Pope Innocent IV, who had moved to Lyon, convened the first Grand Council of Lyon from June 28 to July 17 with the support of Louis. The content of the meeting, apart from the Pope's decision to punish Holy Roman Emperor Frederick II who had conflicts with him, was that Louis announced that he would launch a new round of Crusade, the Seventh Crusade. The spearhead of this Crusade attack is aimed at Egypt. [8]
Louis spent four years preparing to participate in this expedition. After handing over the regency to his mother, he led the French knights and set off on August 25, 1248, carrying his wife and children from Aigues Mortes. His fleet consists of approximately 100 warships, carrying a total of 35000 soldiers. He plans to land in Egypt, capture the main towns of Egypt, and exchange these towns for cities in Syria. His expeditionary force wintered in Cyprus and landed near Damietta at the mouth of the Nile River in Egypt in June 1249. On June 6th, they advanced into the city of Damieta and then headed straight towards Cairo. However, due to the rising water of the Nile River and downstream traffic congestion, he was delayed for several months.

On February 8, 1250, Louis began to capture the fortress of al Mansurah. At this point, the French expeditionary force was already exhausted, and King Robert died in battle. The bodies of thousands of fallen soldiers drifted on the Nile River, and those who did not die were attacked by the plague. Louis had no choice but to order a retreat to Damietta. Later, he himself also contracted an epidemic. The Egyptian army, waiting for work, seized the opportunity to pursue and captured Louis and the remaining French soldiers on April 7th. [8]
After long-term negotiations, Louis IX was released after paying a large amount of ransom and returning Damietta as a condition, and reunited with the queen in Aca. After being released, Louis remained stationed in Christian controlled strongholds in Syria, ready to launch a counterattack, but to no avail. [8]
Carry out reforms
The news of the failure of the Crusades and the capture of Louis spread to France, causing a stir among the farmers. In 1251, northern farmers organized the Poor People's Crusade, calling themselves "shepherds" and opposing feudal lords who oppressed them under the pretext of "rescuing the king.". This team was launched from northern France, entered Paris, and then traveled south from Paris to Orleans and Tours, with poor farmers joining along the way. Wherever they went, they destroyed some monasteries and churches, killed some priests and monks. The Shepherd's Crusade has become a massive peasant uprising. The French court, feudal lords, and Catholic Church joined forces to suppress it, with some "shepherds" fleeing and others killed and captured. In 1252, Regent Empress Blanca died of illness. So, in 1254, Louis returned to Paris from the East.

During Louis's reign, the focus of France's reform in the judicial field was to transfer judicial power to the royal court, stipulating that important cases such as rebellion, imperial edicts, and counterfeiting must be tried by the royal court. Louis prohibited backward customs such as judicial duels and blood revenge, and implemented a "king 40 day" system outside the royal territory: local lords were not allowed to retaliate within 40 days after being violated, and must appeal to the royal court for a ruling by the king. Along with the judicial reform, there was also a currency reform, in which the king stipulated that only the coins of the royal family could circulate in the royal territory. These reform measures have brought more power from local nobles back to the central government, enhanced the prestige of the king, and strengthened royal power. [8]
Louis IX enjoyed great prestige in the Christian world of the West. He began negotiations with King Henry III, who was embroiled in internal turmoil and sidelined by the Mad Council. In October 1259, both sides signed the Treaty of Paris, in which Henry III agreed to abandon the territorial claims of Normandy, Poitou, and Anjou, retaining only a portion of Gascony and Aquitaine, but paying homage to the French king for these territories and recognizing his status as a vassal of the French king. [4] [33]
Louis IX was very concerned about literature and art, and under his encouragement, Vincent of Beauvais wrote the first encyclopedia, the Speculum majus. During his reign, foreign students and scholars gathered at the University of Paris.Died of illness in North Africa
Main entry: Eighth Crusade to the East
During the latter half of Louis IX's reign, he never forgot the holy land. Coinciding with changes in the political and military situation in the Eastern Mediterranean, Louis was forced to make a decision to send troops. Around the summer of 1266, Louis IX had already begun planning a new Crusade to the East. In October of the same year, he secretly informed Pope Clement IV of this decision. On March 25, 1267, Louis announced this decision at a gathering of senior clergy and nobles. At another gathering held on February 9, 1268, he further announced that the Eastern Expedition would depart in May 1270. Some people believe that Charles I of Naples attempted to conquer the revived Byzantine Empire and control both sides of the Sicilian Strait, as well as the passage from the Eastern Mediterranean to the Western Mediterranean. Therefore, he strongly encouraged Louis to designate Tunisia (now the Republic of Tunisia) in North Africa as the attack point for this Crusade. But some historians have also suggested that the convenient use of Sicily played a role... this crusade was both to save and force Muslims to convert, and to conquer the land. At that time, people shifted their preferred religious goals from the farther East to Tunisia. Louis, like his contemporaries, believed that Tunisia was much closer than Egypt and could be used as a land base for future attacks on Sudan. [18] Therefore, he chose Tunisia as the attacking point. [4]
In early July 1270, the French expeditionary force crossed the Mediterranean and landed in Tunisia. In the early stages of the war, the French army was unstoppable, winning consecutive victories and occupying Carthage. But the plague struck again, causing malignant fever and malaria to spread among the Crusaders, while the attacks of dysentery and scurvy left Louis with only one tooth and his body weakened to the point where even getting on a horse was difficult. On July 17th, Louis led his army to the outskirts of Tunis. Starting from August 13th, Louis experienced a relapse of malaria and was unable to recover. He eventually passed away on the same day, at the age of 55 (under 56 years old), on a crib in his tent. [4] [8] It is said that before his death, Louis said, "Oh Jerusalem! Jerusalem! God, you are so kind! May you bless the people living here, and may they not fall into the hands of the enemy or be forced to give up their faith in you." He paused for a moment before continuing, "My God, I entrust my soul to you." [19]

After Louis's death, his body was divided into pieces and boiled in wine and water until the bones and flesh were separated for easy transportation. His body was brought back to France by Prince Philip, passing through the Apennine Peninsula and Lyon in France. Wherever he went, people gathered and knelt down to his remains. In May 1271, the coffin of Louis IX arrived in Paris and a grand funeral was held at Notre Dame Cathedral, where he ultimately rested in the resting place of the Capetian kings - the Church of Saint Denis. [4] Another prince, Charles de Anjou, was responsible for keeping Louis's meat, heart, and other organs safe. He sent someone to transport them to the Monastery of Montreuil in Sicily. [19]
After the death of Louis IX, people did not wait for the judgment of the Roman Catholic Church to consider him a saint and prayed to his tomb. On August 11, 1297, Pope Boniface VIII officially ordered the posthumous canonization of Louis IX as a saint. Louis was the only French king posthumously canonized as a saint by the Vatican.