Professor Frank Holt’s book The Treasures of Alexander the Great: How One Man’s Wealth Shaped the World explains there is little in the historical record on the cost or size of Alexander’s military. Here are a few tidbits which are visible.
Alexander learned to appreciate the value of a Navy. One data point is that in 334 BC he had 200 ships operating in the Aegean sea. No quantification mentioned of naval forces elsewhere at that or any other time.
Figuring out how much Alexander spent to field his military forces is a game of stringing together many wild guesses. The author accumulated his own long string of guesses and assumptions for small units. He also quotes several other studies.
One writer guesses the cost was 5,000 or 7,000 talents per year through 330 BC and 15,000 per year after that. This author’s string of guesses put the total cost around 150,000 to 162,000 talents.
Another author estimated there were 89,000 soldiers and sailors in 334 BC at a cost of 89,000 drachma per day. I calculate that out to 462 talents. (89,000 drachma/day x 6 days/week x 52 weeks / 60,000 drachma per talent = 462.8 Athenian talents). That contains an estimate of an average pay for the army at 1 drachma per day, which is plausible as an average. That wild guess would only include salary, not food, animals, weapons, and other costs of operation.
Yet another author estimates that by 323 Alexander was spending his entire income on the army.
With that valuation, here is the current value of those estimates just mentioned:
First author’s estimates of operating the army:
- $140 billion – 5,000 talents – low range of annual costs before 330
- $196B – 7,000 talents – high range of annual costs before 330
- $420B – 15,000 talents – estimate of annual costs after 330
Second authors estimate of daily costs of salary for the army in 334 BC
- $0.042B – 89,000 drachma – 1.48 Talents – operating costs per day
- $13B – 462.8 Talents – operating costs for a year
The second set of estimates is lower by an order of magnitude, which may be only wages, but still shows the level of uncertainty in estimating ancient finances.