The story begins in A.D. 364 when the author of this memoir, Marcus Cedranus, is born into a middle class landowner's family in western Britain. While his material prospects are promising, his deteriorating relationship with his parents causes him to leave home for the continent. In Gaul he becomes a teamster for a freight hauling company, meets an older woman who will eventually play a major role in his life and is drafted into the Roman army in 382.

He is assigned to Legion XXII in Mainz and in 383 is temporarily transferred to Belgrade on the Danube. A revolt in the west makes this transfer permanent. He participates in several military campaigns and takes part in a triumph in Constantinople in 386. In 388 his regiment takes part in the eastern offensive against the revolt in the west that has by now spread to Italy. With the revolt suppressed, he is assigned to a new imperial guard regiment for the restored western emperor, Valentinian II. During another transfer to the east Marcus suffers a terrible personal tragedy from which it is impossible to recover. Another civil war breaks out in the west and is suppressed with terrible casualties.

Marcus is appointed tribune and made a member of the personal staff of Stilicho, the new generalissimo of the west. Further military adventures take place in Greece, Britain and Italy. A massive barbarian invasion of the west on December 31, 406 triggers political instability leading to revolts in both Britain and Italy. This inevitably leads to the sack of Rome by Alaric and his Visigoths in 410.

A Chronicle of the Roman Twilight