Lucius Cornelius Alexander Polyhistor (Ancient Greek: Ἀλέξανδρος ὁ Πολυΐστωρ; flourished in the first half of the 1st century BC; 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 (very learned). 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.