Lucius Cornelius Alexander Polyhistor (Ancient Greek: Ἀλέξανδρος ὁ Πολυΐστωρ; flourished in the first half of the 1st century B.C.; also called Alexander of Miletus) was a Greek scholar who was enslaved by the Romans during the Mithridatic War and taken to Rome as a tutor. After his release, he continued to live in Italy as a Roman citizen. He was so productive a writer that he earned the surname polyhistor. The majority of his writings are now lost, but the fragments that remain shed valuable light on antiquarian and eastern Mediterranean subjects. Among his works were historical and geographical accounts of nearly all the countries of the ancient world, and the book Upon the Jews (Ancient Greek: Περὶ Ἰουδαίων) which excerpted many works which might otherwise be unknown.
Alexander flourished in the first half of the 1st century B.C. According to the Suda he was a pupil of Crates[disambiguation needed] and a Milesian, whereas Stephanus of Byzantium claims he was a native of Cotiaeum in Lesser Phrygia and a son of Asklepiades, while the Etymologicum Magnum agrees in calling him Kotiaeus. It is possible that two different Alexandroi have been merged or confused. He became a Roman prisoner of war, was sold into slavery to a Cornelius Lentulus as his teacher (paedagogus) and was later freed. As a Roman freedman his name was Cornelius Alexander. The nomen may come from the Corneli Lentuli or from Sulla Felix, as he received the citizenship from Sulla. He died at Laurentum in a fire which consumed his house, and his wife Helene is said by the Suda to have responded to the news of his loss by hanging herself.
The Suda makes no attempt to list his works, asserting that he composed books "beyond number".
Alexander's most important treatise consisted of forty-two books of historical and geographical accounts of nearly all the countries of the ancient world. These included 5 books On Rome, the Aigyptiaca (at least 3 books), On Bithynia, On the Euxine Sea, On Illyria, Indica and a Chaldæan History. Another notable work is about the Jews this reproduces in paraphrase relevant excerpts from Jewish writers, of whom nothing otherwise would be known (see below). As a philosopher, Alexander wrote Successions of Philosophers, mentioned several times by Diogenes Laërtius in his Lives and Opinions of Eminent Philosophers. None of Alexander's works survive as such: only quotations and paraphrases are to be found, largely in the works of Diogenes Laertius. Eusebius extracted a large portion in his Chaldean Chronicle.
One of Alexander’s students was Gaius Julius Hyginus, Latin author, scholar and friend of Ovid, who was appointed by Augustus to be superintendent of the Palatine library. From what Laërtius describes or paraphrases in his work, Alexander recorded various thoughts on contradictions, fate, life, soul and its parts, perfect figures, and different curiosities, such as advice not to eat beans.
Upon the Jews 
Louis Ginzburg wrote of Alexander’s work: “Although these excerpts reveal their author as nothing but a compiler without taste or judgment, and bereft of all literary ability, they possess, even in their meagerness, a certain value.” In his compilation Jewish and non-Jewish sources are cited indiscriminately side by side; and to Alexander, therefore, the world is indebted for information on the oldest Jewish, Hellenic, and Samaritan elaboration of Biblical history in prose or poetry. The epic poet Philo, the tragic writer Ezekiel, the historian Eupolemus, the chronicler Demetrius, the so-called Artapanus, the historian Aristeas, and Theodotus the Samaritan, as well as an unnamed fellow countryman of the latter often confused with Eupolemus, the rhetorician Apollonius Molon (an anti-Jewish writer)—all of these authors are known to posterity only through extracts from their works which Alexander embodied verbatim in his. Of some interest for the ancient history of the Jews is his account of Assyria-Babylonia, frequently drawn upon by Jewish and Christian authors; in it extracts are given, especially from Berosus, and also from the Chronicles of Apollodoros and the Third Book of the Sibyllines. Josephus made use of the work, and likewise Eusebius in his Chronicles. Probably only Alexander's account of the Flood is taken from Berosus, who is confirmed by the newest Assyrian discoveries, while his account of the Confusion of Tongues is probably of Jewish-Hellenic origin. Another work of his seems to have contained considerable information concerning the Jews. What Eusebius quotes would seem to have been taken from this work, which is no longer extant, except indirectly through Josephus. It may be noted that Alexander twice mentions the Bible, which, however, he knew only superficially, as appears from his curious statement that the Law of the Jews was given to them by a woman named Moso, and that Judea received its name from Judah and Idumea, children of Semiramis.
The text of the fragments preserved is in very unsatisfactory shape, owing to insufficient collation of the manuscripts. How much of his originals Alexander himself omitted is difficult to say, in view of the corrupt state of the text of Eusebius, where most of his fragments are to be found. Abydenus—the Christian editor of Alexander’s works—evidently had a different text before him from that which Eusebius possessed.
Text of the fragments Περὶ Ἰουδαίων is to be found in Eusebius, Praeparatio Evangelica, ix. 17; Clemens Alexandrinus, Stromata i. 21, 130, and Müller, Fragmenta Historicorum Graecorum, iii. 211–230; prose extracts, from a new collation of the manuscripts, in Freudenthal, “Alexander Polyhistor,” pp. 219–236.
- Schmitz, Leonhard (1867). "Alexander Cornelius". In William Smith. Dictionary of Greek and Roman Biography and Mythology 1. Boston: Little, Brown and Company. p. 115.
- Servius, ad Aen.X 388 = Jacoby 273 T2
- Diogenes Laërtius, i. 116, ii. 19, 106, iii. 4, 5, iv. 62, vii. 179, viii. 24; ix. 61
- Translation here.
- See Freudenthal, "Alexander Polyhistor" 25.
- Praeparatio Evangelica, ix. 20, 3.
- W. Adler, "Alexander Polyhistor’s Peri Ioudaiôn and Literary Culture in Republican Rome," in Sabrina Inowlocki & Claudio Zamagni (eds), Reconsidering Eusebius: Collected papers on literary, historical, and theological issues (Leiden, Brill, 2011) (Vigiliae Christianae, Supplements, 107),
Other sources 
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Alexander Cornelius". Encyclopædia Britannica (11th ed.). Cambridge University Press.
- Ginzburg, Louis. "Alexander of Miletus". Jewish Encyclopedia. Funk and Wagnalls, 1901–1906, citing:
- Freudenthal, Alexander Polyhistor, Breslau, 1875 (Hellenistische Studien, i. and ii.);
- Unger, "Wann Schrieb Alexander Polyhistor?" in Philologus, xliii. 28-531, ib.xlvii. 177-183;
- Susemihl, Gesch. der Griechischen Literatur, ii. 356-364;
- Schürer, Gesch. 3d ed., iii. 346-349.
- An English translation of the fragments is to be found in Cory's Ancient Fragments, London, 1876;
- a French translation in Reinach, Textes d'Auteurs Grecs et Romains Relatifs au Judaisme, 1895, pp. 65–68.