Diodorus

Diodorus (Diodorus Siculus, approximately 90-30 BC) is one of the historians of Antiquity. He is known as Diodorus Siculus because he was born in Sicily and is known for his work titled Bibliotheke Historike (Vol. 1, p. 28).

Mardians and Cossaeans

Diodorus mentions the Mardians and Cossaeans in the region of Hyrcania; he reports that these tribes were present in units commanded by their own commanders (Vol. 1, p. 29).

In Bibliotheke Historike, Diodorus states that the Mardian tribe was settled in the south and southwest of the region, and recounts the hostilities of the Mardians, along with the Cossaeans, with the Macedonians, that is, the army of Alexander the Great. Diodorus, describing the conflicts between the Persians and the Macedonians, states that the Mardians and Cossaeans, who stood out with their courage and warrior spirit compared to other local elements, gained superiority in a clash against the Macedonians (17.59.1-5). He then describes how Alexander the Great's army, encountering Mardi units serving in the army of the Persian king Darius III in the southwest of the region, drove them towards the remote parts of the mountains (Vol. 1, p. 29).

Comparison with Arrian

Diodorus's accounts are compared with the data of other ancient writers covering the same period. Arrian, just like Diodorus, reports that the Mardians lived close to the Persians, the Uxians to the Susianians, and the Cossaeans to the Medes (Vol. 1, p. 34).