"I sanctify Myself for them, that they also may be sanctified in truth."
St. John 17:19
This Saint was the great-nephew of Saint Louis, King of France, and through his mother, of Saint Elizabeth of Hungary. He was born at Brignoles in Provence, in 1274. From his childhood he made it his earnest study to do nothing which was not directed to the service of God, showing no interest in games and diversions. His walks usually led him to some church or monastery, where he delighted to hear the servants of God discourse on mortification or the most perfect practices of piety. His modesty and recollection in church inspired with devotion all who saw him. When he was only seven years old his mother often found him lying in the night on a mat he spread on the floor near his bed, because he found his bed too soft.
In 1284 the father of Saint Louis, Charles II, was taken prisoner in a sea battle by the King of Aragon. He was released on condition he send into Aragon as hostages, fifty gentlemen and three of his sons. One of these hostages was our Saint. Confined as a prisoner for seven years, he was subjected to ill treatment which never lessened his patience. Louis was finally set at liberty by a treaty concluded between the King of Naples, his father, and James II, King of Aragon. Both courts desired that Louis, then about 18 years old, marry the princess of Majorca, King James' sister. The Saint's resolution to dedicate himself to God was inflexible, however, and he resigned his right to the crown of Naples, begging his father to confer it on his younger brother, Robert.
He had made a vow during a grave illness to join the Friar Minors if cured; this vow was the cause of his recovery. The opposition of his family obliged the superiors of the Friar Minors to refuse for some time to admit him into their body, however, and he therefore went to Naples to prepare for Holy Orders, with his father's permission. Boniface VIII gave him a dispensation to receive priestly orders in the twenty-third year of his age, and afterward sent him a dispensation for the episcopal character also, together with his nomination to the archbishopric of Toulouse, and a severe injunction, in virtue of holy obedience, to accept the same.
Nonetheless, Saint Louis made his religious profession first amid the Friar Minors on Christmas eve of 1296, to fulfill his vow, then received the episcopal consecration the following February. He traveled to his bishopric as a poor religious, but was received at Toulouse with the veneration due to a Saint and the magnificence befitting a prince. His modesty, mildness, and devotion inspired a love of piety in all who beheld him. It was his first concern to provide for the relief of the indigent, and his first visits were made to the hospitals and the poor. In his apostolic labors, he abated none of his austerities and preached frequently. Being obliged to go into Provence for certain very urgent ecclesiastical affairs, he fell ill not far from Marseille. Recognizing that his end was at hand, with tears he received the Viaticum on his knees, and in his last moments ceased not to repeat the Hail Mary. He died August 19, 1297, at the age of twenty-three.
Little Pictorial Lives of the Saints, a compilation based on Butler's Lives of the Saints and other sources by John Gilmary Shea (Benziger Brothers: New York, 1894).