Louis of France (1244–1260)

Louis of France
Prince Louis in prayer; drawing of 13th-century stained glass window in Chartres Cathedral
Regent of France
Tenure	1252–1254
Born	21 or 24 February 1244
Died	11 January 1260(1260-01-11) (aged 15) Paris
Burial	Royaumont Abbey
House	Capet
Father	Louis IX of France
Mother	Margaret of Provence

Louis of France (21 or 24 February 1244 – 11 January 1260) was the eldest son of King Louis IX of France and his wife Margaret of Provence. As heir apparent to the throne, he held regency for a brief period.

In 1248, King Louis and Queen Margaret parents traveled to Egypt to participate in the Seventh Crusade. During their absence, his grandmother, Blanche of Castile, acted as regent. However, when she died in 1252, his parents were still crusading and the eight-year-old Louis was appointed regent. He did not actually rule the country; real power was in the hands of a royal council, led by his uncles Alphonse and Charles. Nevertheless, royal deeds were sealed in his name, and correspondence to the government was addressed to him personally. The basis of the arrangement was the unwritten (at the time) principle of primogeniture in French law: in the absence of written instructions to the contrary, the king's eldest son automatically became regent during the king's absence. This regency ended when Louis IX returned to Paris in 1254.

In subsequent years, Louis was educated for his future role as king. The legal scholar Pierre de Fontaines dedicated his textbook Conseil à un ami to Prince Louis. On 20 August 1255, he was betrothed to Alfonso X of Castile's daughter Berengaria. At the time, she was heir presumptive of Castile. However, shortly after the betrothal, Ferdinand de la Cerda was born, displacing his sister.

Louis and his younger brother Philip witnessed the sealing and oaths confirming the 1259 Treaty of Paris, which was intended to end the territorial conflict between England and France that had been raging since 1180. This treaty required that King Henry III of England pay homage to King Louis IX of France, which he did the following year.