De principis instructione

De principis instructione (Instruction for a Ruler) is a Latin work by Gerald of Wales. It is divided into three "Distinctions". The first contains moral precepts and reflections; the second and third deal with the history of the later 12th century, with a focus on the character and acts of king Henry II of England and especially his disputes with the kings of France, Louis VII and Philip II and with his own four sons, Henry the Young King, Geoffrey, Duke of Brittany, Richard, count of Poitou and John Lackland.

Gerald was learned in classical, Biblical and medieval Latin literature and in this work cites the Bible, Servius (the commentator on Virgil), Gildas, the Itinerarium Regis Ricardi and many other works.

Divided into three distinctions, De principis instructione is a treatise on kingship by Gerald of Wales that serves as a polemical critique of contemporary English governance.^[1] The first distinction takes the form of a "mirror for princes" and is largely derivative, while the second and third distinctions are an extended polemic against Henry II and his heirs, identifying and denouncing their vices.^[2][3] This has led the book to be classified by Jean-Philippe Genet and others as an "anti-mirror", a demonstration of how a prince should not act.^[3]

De principis instructione was first composed in 1191 but was circulated, after revisions, in 1216 or 1217 during the First Barons' War.^[4] This crisis, during which it appeared that the Angevin dynasty was about to be replaced by the French Capetian dynasty, allowed Gerald to write his polemic.^[5]

The extensive revisions resulted in inconsistencies in the work. One instance involves Gerald praying that God will preserve King John "for the tranquil peace of the people and ecclesiastical liberty", but later extensively condemning him for his "wicked tyranny".^[5]

The book was intended as an educational work to instruct princes in governance. The first distinction provides moral teachings derived from earlier authors, while the second and third distinctions provide instruction through historical example.^[4]

It contains a preface inserted late in the writing of the work that dedicates it to Louis VIII of France, then Prince Louis. From this late insertion Charles F. Briggs and Cary J. Nederman contend that the original intention was to have the work undedicated.^[3]

The primary theme of the first distinction is the difference between a good prince and a tyrant, based on differences in moral character. Gerald does this in the first fifteen chapters by listing moral virtues, and then in the remaining six by discussing more generally the difference between good princes and tyrants.^[4]

Throughout this distinction he focuses on temperance, presenting it as a common ground for all virtues, demonstrating his concern of rulers governed by their emotions and the resulting injustice.^[4]

Topics include Britain as a land fertile in tyrants; the Picts and Scots; old English laws about shipwrecks; the recent discovery of King Arthur's tomb in the isle of Avalon; King Edward the Confessor; the virtues of King Louis VII of France

1. The monarch's moderation
2. The monarch's gentleness
3. The monarch's shyness
4. The monarch's chastity
5. The monarch's patience
6. The monarch's temperance
7. The monarch's clemency
8. The monarch's munificence
9. The monarch's magnificence
10. The monarch's justice: especially on the admirable punishment of crimes in France, where a first offence is punished with public whipping, if once repeated with mutilation or branding, if twice repeated with blinding or hanging
11. The monarch's prudence
12. The monarch's foresight
13. The monarch's modesty
14. The monarch's boldness and bravery
15. The monarch's glory and nobility
16. The difference between a king and a tyrant
17. Bloody deaths of tyrants
18. Praiseworthy lives and deaths of good monarchs
19. On the names of monarchs
20. The monarch's religion and devotion: especially on the remarkable chastity of kings Louis VII and Louis VIII of France
21. The monarch's good conduct and fitting end

1. The earlier years of king Henry II of England's reign and the vast increase in his territories
2. Principal visitors to England during his reign
3. His later crimes and the martyrdom of Thomas Becket
4. The wheel of Henry II's fortune and his continual disputes with his sons
5. Letter showing that Louis VII and Henry II agreed to go on pilgrimage to Jerusalem together
6. The two Cardinals who came to Normandy to enquire into the death of Thomas Becket
7. The three monasteries promised in compensation for the failed pilgrimage, and how the promise was evaded
8. God's punishment on Henry II and the death of Henry the Young King
9. The titles of "Henry III" (the Young King)
10. Geoffrey, Duke of Brittany's second estrangement from his father, and his sudden death
11. The titles of Geoffrey and of John Lackland
12. God's warnings to Henry II and how they were ignored
13. The revelation of Robert of Estreby
14. How God urged Henry II to change his ways, with warnings and punishments but also with kindnesses
15. Letter detailing the agreement between Henry II and Philip II of France
16. Letter showing that Henry II arranged peace between Philip II and Philip, Count of Flanders
17. Letter showing that Henry II's testament was made at Waltham
18. Privileges requested from Pope Alexander III, mainly concerning Wales
19. Privileges concerning Ireland
20. The Council of Cashel
21. Titles of Henry II (copied from Gerald's work Topography of Ireland)
22. Saladin's attack on the Kingdom of Jerusalem
23. Pope Urban III's letter to England on this subject
24. Patriarch Heraclius of Jerusalem's visit to England to ask king Henry II's help
25. Pope Lucius III's letter of advice and warning to Henry II
26. Gerald's own conversation with Henry II on this subject
27. Henry II's reply, given at London, and the Patriarch's complete failure
28. The Patriarch's prophetic warnings to Henry II
29. A description and characterization of Henry II
30. Notable contemporary events in England
31. If the end is favourable the history is praiseworthy

1. The last meeting between Louis VII and Henry II, and Louis's prayer
2. First territorial arrangements of Philip II of France
3. Jerusalem meanwhile almost wholly conquered by the Muslims
4. Pope Clement III's letter demanding the aid of the faithful
5. Richard, Duke of Poitou takes the Cross, first among leaders north of the Alps, and sets a noble example
6. On astrology
7. Duke Richard sets out in spite of his father's obstruction
8. Titles of Duke Richard
9. Henry II's tithe intended to finance the Third Crusade
10. Duke Richard estranged from his father and allied with Philip II of France
11. Henry II's confusion and anger
12. Why is Normandy less well defended than in the past? Question and answer
13. King Henry II's groin trouble and his late and forced confession
14. The dream of Richard de Riduariis and its fulfilment
15. Frederick Barbarossa takes the Cross
16. Gerald's dream about the Crusade
17. The Emperor's bravery and his challenge to Saladin
18. Saladin's reply
19. The Emperor's journey through Hungary, crossing of the Danube, and journey through Bulgaria to Macedonia
20. The messengers sent to Isaac II Angelos at first arrested, then released
21. The deceptions of Kilij Arslan II of the Sultanate of Rûm
22. The Emperor drowned in Lesser Armenia; the army reaches Antioch
23. Frederick VI, Duke of Swabia leads them from Antioch to Tyre and Acre
24. Henry II is driven from the burning city of Le Mans
25. The French capture Tours and besiege Henry II at Azay-le-Rideau
26. The death of Henry II
27. The unfavourable family background of Henry II and Queen Eleanor of Aquitaine and of their children
28. Events presaging Henry II's death
29. Dreams presaging his death
30. The dream of William II of England and the resemblance of his death to that of Richard I
31. Some afterthoughts

Gerald used a variety of sources to construct De principis instructione. He frequently references Moralium dogma philosophorum and De officiis by Ambrose of Milan, and was the first author to extensively use both texts. He also references De inventione by Cicero, and Formula vitae honestae by Martin of Braga.^[4]

Istvan P. Bejczy proposes that he also used the definitions of twenty-four virtues by the anonymous author Magister G, a contemporary glossator of Roman law, combined with the definitions in Moralium dogma philosophirum. Hermann Kantorowicz agreed that it was possible Gerald used Magister G as a source, but preferred the argument that they were the same person.^[4]

In the third distinction Gerald describes a letter from Saladin to the Holy Roman Emperor using wording identical to that in Itinerarium Peregrinorum 1. From this Helen J. Nicholson proposes that the Itinerarium was also used as a source for De principis instructione.^[6]

Modern scholars treat De principis instructione as an important work, but it saw limited use in the medieval period with only Ranulph Higden's Polychronicon relying on it. However, the impact of De principis instructione was wider than the surviving manuscript evidence alone would suggest due to the reliance of later authors, including Henry Knighton and John Brompton, on Higden's work.^[5]

It survives in a single manuscript that was produced during the second quarter of the fourteenth century. This manuscript contains Gerald's second, revised edition, and was later owned by John Leland and was bound into Cotton MS Julius B XIII for Robert Cotton with a copy of the Chronicle by Hugh of Saint-Victor and part of the Chronicle of Melrose Abbey.^[7][8]

The work reached its widest audience in the mid-nineteenth century after the second and third distinctions were translated by Joseph Stevenson. A complete translation was published in 2018 by Robert Bartlett.^[5]

• Bartlett, Robert (2018). Gerald of Wales: De principis instructione/Instruction for a Ruler. Oxford: Oxford University Press. ISBN 978-0-19-873862-6.
• Giraldus Cambrensis De instructione principum libri iii. London: Anglia Christiana, 1846. [Book 1 omitted]
• Recueil des historiens des Gaules et de la France vol. 18 ed. M.-J.-J. Brial. New ed. Paris: Palmé, 1879. [Chapters irrelevant to French history omitted]
• Giraldus Cambrensis ed. Brewer (Rolls Series). London
• Bejczy, István P. (2006). "Gerald of Wales on the cardinal virtues: a reappraisal of De principis instructione". Medium Ævum. 75 (2): 191–201. doi:10.2307/43632761. JSTOR 43632761.

• The original Latin chapter headings of De instructione principis (from the Latin Vicipaedia)
• London, British Library, Cotton MS Julius B XIII, ff 48–173: sole surviving manuscript of the work