The exact size of Darius' army is a subject of considerable debate among ancient historians, with estimates varying wildly. There is no single "exact" number agreed upon across all historical accounts; rather, different ancient writers provided significantly different figures, particularly in descriptions of major engagements like the Battle of Gaugamela.
Varying Historical Accounts of Darius' Army Size
Ancient historians offered diverse perspectives on the numerical strength of Darius' forces. These discrepancies highlight the challenges in accurately assessing ancient army sizes, often due to a combination of exaggeration for dramatic effect, logistical difficulties in counting vast armies, and differing source materials available to the historians themselves.
Here's a breakdown of the estimates provided by prominent ancient authors:
| Historian | Cavalry | Infantry | Total Troops | Notes |
|---|---|---|---|---|
| Arrian | 40,000 | 1,000,000 | 1,040,000 | Provides a specific breakdown. |
| Diodorus Siculus | 200,000 | 800,000 | 1,000,000 | Also provides a detailed breakdown. |
| Plutarch | (Not specified) | (Not specified) | 1,000,000 | Mentions total troops without breakdown. |
| Curtius Rufus | 45,000 | 200,000 | 245,000 | Offers a significantly lower estimate. |
As shown, the estimates range from a total of approximately 245,000 troops by Curtius Rufus to over a million by Arrian, Diodorus Siculus, and Plutarch. The most striking difference lies in the estimates for the infantry, with some sources claiming a million foot soldiers while Curtius Rufus records only 200,000. These figures suggest that while Darius commanded a formidable force, the precise scale remains a subject of historical interpretation. The sheer logistical challenge of maintaining and moving armies of such purported sizes also leads many modern historians to view the higher numbers with skepticism, often considering them to be exaggerations.
Understanding the broader context of the Achaemenid Empire provides further insight into the military capabilities of ancient Persia.
