Louis IX (25 April 1214 – 25 August 1270), commonly known as Saint Louis, is the only King of France to be canonized in the Catholic Church.
Louis was crowned in Reims at the age of 12, following the death of his father Louis VIII; his mother, Blanche of Castile, ruled the kingdom as regent until he reached maturity.
During Louis' childhood, Blanche dealt with the opposition of rebellious vassals and obtained a definitive victory in the Albigensian Crusade which had started 20 years earlier.
As an adult, Louis IX faced recurring conflicts with some of the most-powerful nobles, such as Hugh X of Lusignan and Peter of Dreux.
Simultaneously, Henry III of England tried to restore his continental possessions, but was utterly defeated at the battle of Taillebourg.
His reign saw the annexation of several provinces, notably parts of Aquitaine, Maine and Provence.
Louis IX was a reformer and developed French royal justice, in which the king was the supreme judge to whom anyone could appeal to seek the amendment of a judgment.
He banned trials by ordeal, tried to prevent the private wars that were plaguing the country, and introduced the presumption of innocence in criminal procedure.
To enforce the application of this new legal system, Louis IX created provosts and bailiffs.
Following a vow he made after a serious illness and confirmed after a miraculous cure, Louis IX took an active part in the Seventh and Eighth Crusades.
He died from dysentery during the latter crusade, and was succeeded by his son Philip III.
Louis's actions were inspired by Christian zeal and Catholic devotion.
He decided to severely punish blasphemy (for which he set the punishment to mutilation of the tongue and lips), gambling, interest-bearing loans and prostitution.
He spent exorbitant sums on presumed relics of Christ, for which he built the Sainte-Chapelle.
He expanded the scope of the Inquisition and ordered the burning of Talmuds and other Jewish books.
He is the only canonized king of France, and there are consequently many places named after him.