The Cyropaedia (or Cyropedia) is a biography of Cyrus the Great, written in the early 4th century BC by the Athenian gentleman-soldier, and student of Socrates, Xenophon of Athens. The Latinized title Cyropaedia derives from Greek Kúrou paideía (Κύρου παιδεία), meaning "The Education of Cyrus". Aspects of it would become a model for medieval writers of the genre known as mirrors for princes. In turn it was a strong influence upon the most well-known but atypical of these, Machiavelli's The Prince, which was an important influence in the rejection of medieval political thinking, and the development of modern politics. However, unlike most "mirrors of princes", and like The Prince, whether or not the Cyropaedia was really intended to describe an ideal ruler is a subject of debate.
In substance, the Cyropaedia is "a political romance, describing the education of the ideal ruler, trained to rule as a benevolent despot over his admiring and willing subjects."
Although it is "generally agreed" that Xenophon "did not intend Cyropaedia as history", it remains unclear whether this work was intended to fit into any other classical genre known before. Its validity as a source of Achaemenid history has been repeatedly questioned, and numerous descriptions of events or persons have been determined to be in error. But it is not clear that the work was intended to be used this way.
Despite such doubts, it has been argued that Xenophon's Cyropaedia offers a glimpse of the character of Cyrus the Great of Achaemenid Persia. The source gives "an artist's portrait" of Cyrus as "the Ideal Ruler and the best form of Government", a description that "could not have been painted had there not been a credible memory of such a Cyrus". Xenophon (c. 431 – 355 BC) was not a contemporary of Cyrus (c. 580 – 530 BC) and it is likely that at least some of the information about Persia was based on events that occurred at the later Achaemenid court. Xenophon had been in Persia himself, as part of the "Ten Thousand" Greek soldiers who fought on the losing side in a Persian civil war, events which he recounted in his Anabasis. It is also possible that stories of the great King were recounted (and embellished) by court society and that these are the basis of Xenophon's text.
The book opens with the author stating that the work started as a reflection about what it is that makes people willingly obey some rulers and not others. Everywhere, the author observes, humans fail to obey their rulers; the one exception is Cyrus, king of the Persians, "who reduced to obedience a vast number of men and cities and nations".  There then follows a list of the king's conquests, and the author seeks to understand why his subjects obeyed him "willingly". The work narrates the king's entire life, and so only the first of the 8 books concerns the "education of Cyrus" (cyropaedia) strictly speaking. This first book is devoted to Cyrus' descent, education and his stay at the court of his maternal grandfather, the Median dynast Astyages. It has been noted by scholars that Xenophon's description of Persian education in their pre-imperial time is strikingly unusual, and appears to be based upon the traditions of Sparta, the subject of Xenophon's own work the Constitution of the Lacedemonians.
Books 2 through 7 cover Cyrus' life while still an important vassal of the Medes, on his career towards establishing the largest empire the world had known until that date. It is in this main part of the work that the character Cyrus is often shown as an example of classical virtue, but is also at the same time often seen as showing Machiavellian tendencies. In this version of events, Cyrus is a faithful vassal to the Medes, someone who initially helps them as a general to defend themselves from a much more powerful and assertive Babylonian empire, which was being ruled by the tyrannical son of a more respected king. He does this partly by carefully building up alliances with nations such as the Armenians, their neighbours whom he referred to as Chaldeans, Hyrcanians, Cadusians, Saka, and Susians. The remaining allies of Babylon included many nations of Asia Minor, as well as a corps of Egyptian infantry. For their final great field battle, Croesus of Lydia was general. Cyrus then returns with an increasingly international army to Babylon, and is able to avoid a long siege by deflecting the course of the river through it, and then sending soldiers in over the dry bed, during a festival night. (This is significantly different from how the real events are understood to have been.)
Book 8 is a sketch of Cyrus' kingship and his views of monarchy. This last book of the work also describes the rapid collapse of the empire of Cyrus after he died. It has sometimes been argued to be by another later author, or alternatively to be either a sign of Xenophon's theoretical inconsistency concerning his conception of an ideal ruler, or a sign that Xenophon did not mean to describe an ideal ruler in any simple way.
Other related characters, of questionable historical truth, appear in the narrative as well. For example, the romance of Abradatas and Pantheia forms a part of the latter half of the narrative (v.1.3, vi.1.31ff, vi.4.2ff, vii.3.2ff).
In classical antiquity, the Cyropaedia was considered the masterpiece of a very widely respected and studied author. Polybius, Cicero, Tacitus, Dionysius of Halicarnassus, Quintilian, Aulus Gellius and Longinus "ranked him among the best philosophers and historians". Classical authors believed that Xenophon composed it in response to the Republic of Plato, or vice versa, and Plato's Laws seems to allude to the Cyropaedia. Amongst classical leaders, Scipio Aemilianus is said to have carried a copy with him at all times, and it was also a favourite of Alexander the Great and Julius Caesar.
The Cyropaedia was rediscovered in Western Europe during the late medieval period as a practical treatise on political virtue and social organization. It became an important influence upon the late medieval and Renaissance genre known as "mirrors of princes", which attempted to give examples of behavior in order to educate young future rulers. Giovanni Pontano, Bartolomeo Sacchi, Leon Battista Alberti and Baldassare Castiglione all treated Cyrus as an example of virtue.
The work continued to be widely read and respected in the early modern period and during the Enlightenment. Machiavelli's The Prince, which represented a turning point towards modern political thinking, uses the mirror genre as a model, is particularly heavily influenced by the Cyropaedia, and represented a more sophisticated reading of Xenophon, apparently more critical of the idealistic approach on the surface of Xenophon's depiction, while also reading Xenophon to be giving other more important messages about Cyrus's use of deceit, and the danger of such men to republics. Christopher Nadon, currently considered the foremost authority on Xenophon, describes Machiavelli as "Xenophon's best-known and most devoted reader". According to Leo Strauss, Machiavelli refers to Xenophon more than the better known authors Plato, Aristotle, and Cicero put together. Gilbert (1938, p. 236) wrote: "The Cyrus of Xenophon was a hero to many a literary man of the sixteenth century, but for Machiavelli he lived".
Among early modern writers after Machiavelli, Montaigne, Montesquieu, Rousseau, Bacon, Jonathan Swift, Bolingbroke, Shaftesbury, Edward Gibbon, and Benjamin Franklin "all concurred with the classical view" of Xenophon's merits as a philosopher and historian. John Milton called his works divine, and the equal of Plato. Edmund Spenser in his preface to The Faerie Queene said that "Xenophon's Cyropaedia is to be preferred to Plato.[n 1] Among military leaders, Gustavus Adolphus and James Wolfe were influenced by this work.
The work was also frequently taken as a model for correct prose style in classical Attic Greek, mastery of which was part of the cultivation of learning and refinement among gentlemen in eighteenth century Europe and America. For example, Thomas Jefferson had two personal copies of the book in his library, possibly for this reason. In modern times, its reputation has declined, together with the study of the classics; it has been described as "surely one of the most tedious books to have survived from the ancient world," a view countered by others, such as Potter, who found it "written in the most captivating, simple and elegant style imaginable."
In the nineteenth century, Xenophon and the Cyropaedia began to be seen as inferior to comparable classical authors and works, and not deserving of the older reputation. This was at least partly because works such as the Cyropaedia discuss historical subjects but are not apparently historically accurate.
- The original reads: "For this cause is Xenophon preferred before Plato, for that the one, in the exquisite depth of his judgement, formed a Commune welth, such as it should be; but the other in the person of Cyrus, and the Persians, fashioned a government, such as might best be: So much more profitable and gratious is doctrine by example, then by rule."
- Sancisi-Weerdenburg, Heleen (1993), "Cyropaedia", Encyclopaedia Iranica 6.5, Costa Mesa: Mazda
- Xenophon (1914), Miller, Walter, ed., Cyropaedia: The Education of Cyrus, London: William Heinemann Ltd.
- Nadon, Christopher (2001), Xenophon's Prince: Republic and Empire in the Cyropaedia, Berkeley: UC Press, ISBN 0-520-22404-3
- Mallowan, Max (1985), "Cyrus the Great", in Ilya Gershevitch, William Bayne Fisher, J. A. Boyle, The Cambridge History of Iran 2, Cambridge University Press, ISBN 0-521-20091-1 p. 417.
- Smith, William (1867), "Abradatas", in Smith, William, Dictionary of Greek and Roman Biography and Mythology 1, p. 3
- Nadon (2001, p. 4)
- Nadon (2001, p. 3)
- Diogenes Laertius (3.34)
- Cawkwell, George (1972), The Persian Expedition (introduction), Penguin Classics
- Nadon (2001, p. 6)
- Nadon (2001, p. 13)
- Gilbert, Allan (1938), Machiavelli's Prince and Its Forerunners, Duke University Press p.12
- Nadon (2001, pp. 6–7)
- Nadon (2001, pp. 13–25)
- Strauss, Leo (1958), Thoughts on Machiavelli, University of Chicago Press p.291
- Rezakhani, Khodadad (2013). "Cyrus: the Tale of a Cylinder". Iran Opinion, May 2013. 
- John Potter, Archaeologia Graeca, or The Antiquities of Greece, Vol. II, p. 101 
- Xenophon (2012), Cyrus' Paradise: The World's First Online Collaborative Commentary to an Ancient Text, Washington
- Xenophon (1997), Miller, Walter, trans., ed., Cyropaedia, Cambridge: Harvard University Press, ISBN 978-0-674-99057-9, ISBN 0-674-99057-9 (books 1-5) and ISBN 978-0-674-99058-6, ISBN 0-674-99058-7 (books 5-8)
- Xenophon (2001), Ambler, Wayne, trans., ed., The Education of Cyrus, Ithaca: Cornell University Press, ISBN 0-8014-8750-1
- Xenophon (1914), Dakyns, Henry Graham, trans., Stawell, F. M., ed., Cyropaedia: The Education of Cyrus, London: Macmillan [Project Gutenberg]
- Xenophon (1914), Miller, Walter, ed., Cyropaedia: The Education of Cyrus, London and Cambridge, MA: William Heinemann Ltd. and Harvard University Press [Perseus/Tufts University]