Louis IX of France, also known as Saint Louis, was a king who reigned from 1226 to 1270. He is remembered for his strong sense of justice, commitment to the Christian faith, and efforts to improve the lives of his subjects. Louis IX led two crusades and was known for his piety and dedication to the Church. He was canonized as a saint by the Catholic Church in 1297, making him one of the few monarchs to be recognized as a saint. His legacy includes the establishment of the Saint Louis Cathedral in Paris and various legal reforms that influenced French law.