Louis IX of France

Louis IX reigned over the Kingdom of France for more than four decades, from 1226 to 1270, at a time when it was the richest and most powerful realm in western Christendom. Remembered as Saint Louis, he is the only French king ever canonised. His reputation rests on his reforms of royal justice and his personal piety, though that piety also drove two failed crusades and harsh measures against the kingdom's Jews.

Louis was born at Poissy, near Paris, on 25 April 1214, a grandson of Philip II. His father, Louis VIII, died in November 1226, and the twelve-year-old was crowned at Reims later that month. His mother, Blanche of Castile, governed as regent. She faced down rebellious barons and in 1229 closed the long Albigensian Crusade in the south through a settlement with Raymond VII of Toulouse. In 1234 Louis married Margaret of Provence, and historians usually date his personal rule from that year, although Blanche remained a powerful adviser until her death in 1252.

Louis's lasting domestic legacy was legal. He let subjects appeal to royal courts, banned trial by ordeal and by combat, and tried to stop private wars between nobles. Before leaving on crusade in 1248 he sent investigators, the enquêteurs, across France to hear complaints against royal officials, and in December 1254 he issued a great ordinance setting rules of conduct for his bailiffs and other officers. Stories describe him hearing cases himself beneath an oak in the forest of Vincennes. When the lord of Coucy hanged three young men for poaching without trial, Louis had him arrested and fined 12,000 livres.

His devotion was intense. Between 1239 and 1241 he acquired the Crown of Thorns, paying 135,000 livres to clear a debt for which it had been pledged, and built the Sainte-Chapelle in Paris to house it; the chapel was consecrated in 1248. He also founded hospitals and fed the poor at his table. The same zeal had a darker side. He banned lending at interest and used the ban to extract money from Jewish and Lombard lenders, oversaw the Disputation of Paris in 1240, and in 1242 had thousands of copies of the Talmud burned. He extended the Inquisition, punished blasphemy with mutilation, and ordered Jews to wear a distinguishing badge.

Louis took the cross after surviving a serious illness. His army reached Egypt in June 1249 and seized Damietta, but the advance towards Cairo stalled in the Nile Delta, and in 1250 his army was destroyed and he was taken prisoner. He was freed for a ransom of 400,000 bezants, roughly the crown's yearly income, and the return of Damietta. During the campaign power in Egypt passed from the Ayyubids to the Mamluks. Louis then spent four years strengthening crusader towns such as Acre and Jaffa, and exchanged envoys with the Mongols, sending the friar William of Rubruck to the court of the Great Khan.

Back in France in 1254, he settled old quarrels by treaty. At Corbeil in 1258 he and James I of Aragon gave up rival claims north and south of the Pyrenees. The Treaty of Paris of 1259 had Henry III of England renounce Normandy, Anjou, Maine, Touraine and Poitou in return for holding Gascony as Louis's vassal. His reputation for fairness made him Europe's favoured arbiter, though his 1264 ruling for Henry against the English barons failed to prevent civil war. His relations with Frederick II, by contrast, were cool.

In 1267 Louis took the cross again and chose to attack Tunis, ruled by the Hafsid dynasty. His army landed near Carthage in July 1270, disease swept the camp, and he died of dysentery on 25 August 1270. His son Philip III succeeded him, and Pope Boniface VIII canonised him in 1297.

Our 1200 map shows the French kingdom shortly before his birth, and the 1279 map shows it nine years after his death, enlarged by the lands his grandfather had taken from the English kings.