Saint Louis IX was the King of France from 1226 until his death in 1270. He is known for his strong sense of justice, commitment to the Christian faith, and efforts to improve the welfare of his subjects. Louis led two crusades, aiming to reclaim the Holy Land, and is remembered for his piety and dedication to the Church. He was canonized as a saint by the Catholic Church in 1297, making him the only French king to be recognized as a saint. His legacy includes the establishment of the Sainte-Chapelle in Paris, a stunning Gothic chapel that houses relics of the Passion of Christ.