Diodorus Siculus (Διόδωρος ὁ Σικελιώτης) was a Greek historian from Agyrium in Sicily who flourished in the 1st century BCE during the time of Julius Caesar and Augustus. He traveled extensively in Asia and Europe and resided in Rome to research his universal history, where he accessed written sources and learned Latin [1][2]. His life is known almost exclusively from his own writings [2].

His sole surviving work is the Bibliotheca historica (Βιβλιοθήκη ἱστορική), a 40-book universal history spanning from mythological times to 60/59 BCE. Only Books 1–5 and 11–20 survive intact, with fragments remaining of the others [1][2][3].

Diodorus is significant as the compiler of one of the few surviving universal histories from antiquity. His work is an indispensable, if not always critically rigorous, source for Sicilian, Greek, and Hellenistic history, preserving valuable fragments from lost historians like Ephorus and Hieronymus of Cardia [1][2]. Intended for moral instruction, his history remains a crucial narrative for periods where other sources are lacking [1][2][3].

Sources 1. Encyclopædia Britannica: Diodorus Siculus. https://www.britannica.com/biography/Diodorus-Siculus 2. Oxford Research Encyclopedia of Classics: Diodorus Siculus. https://oxfordre.com/classics/view/10.1093/acrefore/9780199381135.001.0001/acrefore-9780199381135-e-2255 3. World History Encyclopedia: Diodorus Siculus. https://www.worldhistory.org/Diodorus_Siculus/