Antonius Diogenes

c. 2nd century–c. 2nd century

Antonius Diogenes was an ancient Greek writer, probably active in the Roman imperial period, about whose life almost nothing certain is known. He composed The Wonders Beyond Thule, a long prose romance involving distant travel, marvels, mistaken deaths and nested narratives. The complete work is lost, but a detailed summary by the ninth-century scholar Photius shows that it belonged to the early tradition from which the later European adventure and romance novel developed.

Antonius is more important to the history of fiction as an author than as a character in historical novels. No widely known modern novel places him at its centre, but The Wonders Beyond Thule is frequently discussed alongside works by Chariton, Longus and Heliodorus as evidence that complex prose fiction flourished in antiquity. A fictional treatment of his life would necessarily be highly imaginative because the surviving evidence provides almost no personal biography.