Louis was king for 44 years, being crowned at age 12; his mother ruled as regent until he reached 22. He founded monasteries, built leper hospitals, fed from his own tables over 100 poor people each day, and collected relics. He was married at age 19, and fathered eleven children. His great holiness was manifest to all, so much so that it took only 27 years for the Church to canonize him.
St. Louis led an exemplary life, bearing constantly in mind his mother's words: "I would rather see you dead at my feet than guilty of a mortal sin." His biographers have written much about the long hours he spent in prayer, fasting, and penance, without the knowledge of his subjects.
His “social doctrine” is something he summed up as follows: “In prosperity, give thanks to God with humility and fear lest by pride you abuse God's benefits and so offend him.”
His faith and devotion can be immediately grasped through a letter he wrote to his son while fighting the infidel in the Holy Land:
My dearest son, my first instruction is that you should love the Lord your God with all your heart and all your strength. Without this there is no salvation. Keep yourself, my son, from everything that you know displeases God, that is to say, from every mortal sin. You should permit yourself to be tormented by every kind of martyrdom before you would allow yourself to commit a mortal sin.
If the Lord has permitted you to have some trial, bear it willingly and with gratitude, considering that it has happened for your good and that perhaps you well deserved it. If the Lord bestows upon you any kind of prosperity, thank him humbly and see that you become no worse for it, either though vain pride or anything else, because you ought not to oppose God or offend him in the matter of his gifts.
Be kindhearted to the poor, the unfortunate and the afflicted. Give them as much help and consolation as you can. Thank God for all the benefits he has bestowed upon you, that you may be worthy to receive greater. Always side with the poor rather than with the rich, until you are certain of the truth.
Be devout and obedient to our mother the Church of Rome and the Supreme Pontiff as your spiritual father.
In conclusion, dearest son, I give you every blessing that a loving father can give a son. May the three Persons of the Holy Trinity and all the saints protect you from every evil. And may the Lord give you the grace to do his will so that he may be served and honored through you, that in the next life we may together come to see him, love him and praise him unceasingly. Amen.
St. Louis, Pray for us