The following is King Louis IX’s beautiful letter to his son, who would later become Phillip III, exhorting him to to be a good and just King and Ruler by practicing holiness and avoiding sin, while admonishing him to love the Holy Catholic Church, which it is his duty to defend.
1. To his dear first-born son, Philip, greeting, and his father’s love.
2. Dear son, since I desire with all my heart that you be well “instructed in all things, it is in my thought to give you some advice in this writing. For I have heard you say, several times, that you remember my words better than those of any one else.
3. Therefore, dear son, the first thing I advise is that you fix your whole heart upon God, and love Him with all your strength, for without this no one can be saved or be of any worth.
4. You should, with all your strength, shun everything which you believe to be displeasing to Him. And you ought especially to be resolved not to commit mortal sin, no matter what may happen and should permit all your limbs to be hewn off, and suffer every manner of torment, rather than fall knowingly into mortal sin.
5. If our Lord send you any adversity, whether illness or other in good patience, you should receive it in good patience and be thankful for it, for you ought to believe that He will cause everything to turn out for your good; and likewise you should think that you have well merited it, and more also, should He will it, because you have loved Him but little, and served Him but little, and have done many things contrary to His will.
6. If our Lord send you any prosperity, either health of body or other thing you ought to thank Him humbly for it, and you ought to be careful that you are not the worse for it, either through pride or anything else, for it is a very great sin to fight against our Lord with His gifts.
7. Dear son, I advise you that you accustom yourself to frequent confession, and that you choose always, as your confessors, men who are upright and sufficiently learned, and who can teach you what you should do and what you should avoid. You should so carry yourself that your confessors and other friends may dare confidently to reprove you and show you your faults.
8. Dear son, I advise you that you listen willingly and devoutly the services of Holy Church, and, when you are in church, avoid to frivolity and trifling, and do not look here and there; but pray to God with lips and heart alike, while entertaining sweet thoughts about Him, and especially at the mass, when the body and blood of our Lord Jesus Christ are consecrated, and for a little time before.
9. Dear son, have a tender pitiful heart for the poor, and for all those whom you believe to be in misery of heart or body, and, according to your ability, comfort and aid them with some alms.
10. Maintain the good customs of your realm, and put down the bad ones. Do not oppress your people and do not burden them with tolls or tailles, except under very great necessity.
11. If you have any unrest of heart, of such a nature that it may be told, tell it to your confessor, or to some upright man who can keep your secret; you will be able to carry more easily the thought of your heart.
12. See to it that those of your household are upright and loyal, and remember the Scripture, which says: “Elige viros timentes Deum in quibus sit justicia et qui oderint avariciam”; that is to say, “Love those who serve God and who render strict justice and hate covetousness”; and you will profit, and will govern your kingdom well.
13. Dear son, see to it that all your associates are upright, whether clerics or laymen, and have frequent good converse with them; and flee the society of the bad. And listen willingly to the word of God, both in open and in secret; and purchase freely prayers and pardons.
14. Love all good, and hate all evil, in whomsoever it may be.
15. Let no one be so bold as to say, in your presence, words which attract and lead to sin, and do not permit words of detraction to be spoken of another behind his back.
!6. Suffer it not that any ill be spoken of God or His saints in your presence, without taking prompt vengeance. But if the offender be a clerk or so great a person that you ought not to try him, report the matter to him who is entitled to judge it.
17. Dear son, give thanks to God often for all the good things He has done for you, so that you may be worthy to receive more, in such a manner that if it please the Lord that you come to the burden and honor of governing the kingdom, you may be worthy to receive the sacred unction wherewith the kings of France are consecrated.
18. Dear son, if you come to the throne, strive to have that which befits a king, that is to say, that in justice and rectitude you hold yourself steadfast and loyal toward your subjects and your vassals, without turning either to the right or to the left, but always straight, whatever may happen. And if a poor man have a quarrel with a rich man, sustain the poor rather than the rich, until the truth is made clear, and when you know the truth, do justice to them.
19. If any one have entered into a suit against you (for any injury or wrong which he may believe that you have done to him), be always for him and against yourself in the presence of your council, without showing that you think much of your case (until the truth be made known concerning it); for those of your council might be backward in speaking against you, and this you should not wish; and command your judges that you be not in any way upheld more than any others, for thus will your councillors judge more boldly according to right and truth.
20. If you have anything belonging to another, either of yourself or through your predecessors, if the matter is certain, give it up without delay, however great it may be, either in land or money or otherwise. If the matter is doubtful, have it inquired into by wise men, promptly and diligently. And if the affair is so obscure that you cannot know the truth, make such a settlement, by the counsel of upright men, that your soul, and the soul your predecessors, may be wholly freed from the affair. And even if you hear some one say that your predecessors made restitution, make diligent inquiry to learn if anything remains to be restored; and if you find that such is the case, cause it to be delivered over at once, for the liberation of your soul and the souls of your predecessors.
21. You should seek earnestly how your vassals and your subjects may live in peace and rectitude beneath your sway; likewise, the good towns and the good cities of your kingdom. And preserve them in the estate and the liberty in which your predecessors kept them, redress it, and if there be anything to amend, amend and preserve their favor and their love. For it is by the strength and the riches of your good cities and your good towns that the native and the foreigner, especially your peers and your barons, are deterred from doing ill to you. I will remember that Paris and the good towns of my kingdom aided me against the barons, when I was newly crowned.
22. Honor and love all the people of Holy Church, and be careful that no violence be done to them, and that their gifts and alms, which your predecessors have bestowed upon them, be not taken away or diminished. And I wish here to tell you what is related concerning King Philip, my ancestor, as one of his council, who said he heard it, told it to me. The king, one day, was with his privy council, and he was there who told me these words. And one of the king’s councillors said to him how much wrong and loss he suffered from those of Holy Church, in that they took away his rights and lessened the jurisdiction of his court; and they marveled greatly how he endured it. And the good king answered: “I am quite certain that they do me much wrong, but when I consider the goodnesses and kindnesses which God has done me, I had rather that my rights should go, than have a contention or awaken a quarrel with Holy Church.” And this I tell to you that you may not lightly believe anything against the people of Holy Church; so love them and honor them and watch over them that they may in peace do the service of our Lord.
23. Moreover, I advise you to love dearly the clergy, and, so far as you are able, do good to them in their necessities, and likewise love those by whom God is most honored and served, and by whom the Faith is preached and exalted.
24. Dear son, I advise that you love and reverence your father and your mother, willingly remember and keep their commandments, and be inclined to believe their good counsels.
25. Love your brothers, and always wish their well-being and their good advancement, and also be to them in the place of a father, to instruct them in all good. But be watchful lest, for the love which you bear to one, you turn aside from right doing, and do to the others that which is not meet.
26. Dear son, I advise you to bestow the benefices of Holy Church which you have to give, upon good persons, of good and clean life, and that you bestow them with the high counsel of upright men. And I am of the opinion that it is preferable to give them to those who hold nothing of Holy Church, rather than to others. For, if you inquire diligently, you will find enough of those who have nothing who will use wisely that entrusted to them.
27. Dear son, I advise you that you try with all your strength to avoid warring against any Christian man, unless he have done you too much ill. And if wrong be done you, try several ways to see if you can find how you can secure your rights, before you make war; and act thus in order to avoid the sins which are committed in warfare.
28. And if it fall out that it is needful that you should make war (either because some one of your vassals has failed to plead his case in your court, or because he has done wrong to some church or to some poor person, or to any other person whatsoever, and is unwilling to make amends out of regard for you, or for any other reasonable cause), whatever the reason for which it is necessary for you to make war, give diligent command that the poor folk who have done no wrong or crime be protected from damage to their vines, either through fire or otherwise, for it were more fitting that you should constrain the wrongdoer by taking his own property (either towns or castles, by force of siege), than that you should devastate the property of poor people. And be careful not to start the war before you have good counsel that the cause is most reasonable, and before you have summoned the offender to make amends, and have waited as long as you should. And if he ask mercy, you ought to pardon him, and accept his amende, so that God may be pleased with you.
29. Dear son, I advise you to appease wars and contentions, whether they be yours or those of your subjects, just as quickly as may be, for it is a thing most pleasing to our Lord. And Monsignore Martin gave us a very great example of this. For, one time, when our Lord made it known to him that he was about to die, he set out to make peace between certain clerks of his archbishopric, and he was of the opinion that in so doing he was giving a good end to life.
30. Seek diligently, most sweet son, to have good baillis and good prevots in your land, and inquire frequently concerning their doings, and how they conduct themselves, and if they administer justice well, and do no wrong to any one, nor anything which they ought not do. Inquire more often concerning those of your household if they be too covetous or too arrogant; for it is natural that the members should seek to imitate their chief; that is, when the master is wise and well-behaved, all those of his household follow his example and prefer it. For however much you ought to hate evil in others, you shoud have more hatred for the evil which comes from those who derive their power from you, than you bear to the evil of others; and the more ought you to be on your guard and prevent this from happening.
3!. Dear son, I advise you always to be devoted to the Church of Rome, and to the sovereign pontiff, our father, and to bear him the the reverence and honor which you owe to your spiritual father.
32. Dear son, freely give power to persons of good character, who know how to use it well, and strive to have wickednesses expelled from your land, that is to say, nasty oaths, and everything said or done against God or our Lady or the saints. In a wise and proper manner put a stop, in your land, to bodily sins, dicing, taverns, and other sins. Put down heresy so far as you can, and hold in especial abhorrence Jews, and all sorts of people who are hostile to the Faith, so that your land may be well purged of them, in such manner as, by the sage counsel of good people, may appear to you advisable.
33. Further the right with all your strength. Moreover I admonish you you that you strive most earnestly to show your gratitude for the benefits which our Lord has bestowed upon you, and that you may know how to give Him thanks therefore
34. Dear son, take care that the expenses of your household are reasonable and moderate, and that its moneys are justly obtained. And there is one opinion that I deeply wish you to entertain, that is to say, that you keep yourself free from foolish expenses and evil exactions, and that your money should be well expended and well acquired. And this opinion, together with other opinions which are suitable and profitable, I pray that our Lord may teach you.
35. Finally, most sweet son, I conjure and require you that, if it please our Lord that I should die before you, you have my soul succored with masses and orisons, and that you send through the congregations of the kingdom of France, and demand their prayers for my soul, and that you grant me a special and full part in all the good deeds which you perform.
36. In conclusion, dear son, I give you all the blessings which a good and tender father can give to a son, and I pray our Lord Jesus Christ, by His mercy, by the prayers and merits of His blessed Mother, the Virgin Mary, and of angels and archangels and of all the saints, to guard and protect you from doing anything contrary to His will, and to give you grace to do it always, so that He may be honored and served by you. And this may He do to me as to you, by His great bounty, so that after this mortal life we may be able to be together with Him in the eternal life, and see Him, love Him, and praise Him without end. Amen. And glory, honor, and praise be to Him who is one God with the Father and the Holy Spirit; without beginning and without end. Amen.
From Saint Louis’ Advice to His Son, in Medieval Civilization, trans. and eds. Dana Munro and George Clarke Sellery (New York: The Century Company, 1910), pp. 366 -75.