Flavius Eutropius was an Ancient Roman historian who flourished in the latter half of the 4th century AD. He held the office of secretary (magister memoriae) at Constantinople, accompanied the Emperor Julian (361–363) on his expedition against the Persians (363), and was alive during the reign of Valens (364–378), to whom he dedicates his Breviarium historiae Romanae and where his history ends. Possibly he held higher state offices in later years, becoming Praetorian prefect for Illyria in 380 and - together with emperor Valentinian II - consul in 387. However, it is a question of academic discussion whether the Eutropius holding these offices is really to be identified with the historian.
The Breviarium historiae Romanae is a complete compendium, in ten books, of Roman history from the foundation of the city to the accession of Valens. It was compiled with considerable care from the best accessible authorities, and is written generally with impartiality, and in a clear and simple style. Although the Latin in some instances differs from that of the purest models, the work was for a long time a favorite elementary school-book. Its independent value is small, but it sometimes fills a gap left by the more authoritative records. For the Republican period, Eutropius depended upon an epitome of Livy; for the later parts, he appears to have used Suetonius and the now lost Enmannsche Kaisergeschichte. For the end he could also make use of his own personal experience. The Breviarium was enlarged and continued down to the time of Eastern Roman Emperor Justinian the Great by Paulus Diaconus; the work of the latter was in turn enlarged by Landolfus Sagax (c. 1000), and taken down to the time of the emperor Leo the Armenian (813–820) in the Historia Miscella.
Of the Greek translations by Paeanius (around 380) and Capito Lycius (6th century), the version of the former is extant in an almost complete state. The best edition of Eutropius is by H. Droysen (1879), containing the Greek version and the enlarged editions of Paulus Diaconus and Landolfus. There are also numerous English editions and translations.