The Logistics of the Macedonian Army by Donald Engels

My latest book was Alexander the Great and the Logistics of the Macedonian Army by Donald W. Engels. This book focuses purely on the logistics of Alexander’s conquests and how the need for supply dictated campaign planning and strategy, particularly given the incredibly brutal terrain that Alexander was often marching through. The author skips over any campaign in which it was clear there were no supply issues and provides no overall summary of Alexander’s life or campaigns. The reader is assumed to come equipped with a good working knowledge of Alexander the Great and his campaigns.

The introductory chapter includes an excellent discussion about sources which I talked briefly about in my comments on JFC Fuller’s book on Alexander here (link). Engels argues persuasively that both the traditional sources like Arrian and the Vulgate sources have value. Quintus Curtius Rufus, who wrote Histories of Alexander the Great in the first century A.D., is singled out as having excellent geographical data. Curtius’s description of travel in various areas conquered by Alexander match the experiences of modern travelers, and, according to Engels, the climate in these regions is the same now as it was then, even if flora and fauna have changed due to different patterns of agricultural settlement.

As was often the case, the author argues that Alexander must have been supplied by water during the siege of Tyre.

Engels begins by breaking down the precise food and water requirements that would be needed to keep men and pack animals alive in regular terrain and in desert and uses those figures to calculate how much Alexander’s army would need to carry for various marches. He goes about this in a highly systematic way, breaking down carrying capacity of men and beasts, mathematically calculating weight, and relying on a number of modern studies of military nutrition. He even examines the nutritional/caloric value of the types rations likely to be carried by Alexander’s armies.

From these, he’s able to reach some really interesting global conclusions that (although he doesn’t press this argument) can be applied globally to the ancient world, particularly prior to the invention of the shoulder harness for pack animals. Even after that point, only minor modifications would be needed (e.g. carrying capacity of horses with better tack) to apply his conclusions to warfare and logistics prior to mechanization—so say to everything more than about 180 years ago.

A few interesting conclusions follow. The overall size of an army is irrelevant to determining the maximum amount of time that it can march without resupplying. This is because the limiting factor on this determination is the amount that a man can carry to begin the March (80 pounds), and you can calculate from there how many days he can go before running out of food. From this, Engels concludes that maximum grain supply would be two weeks. He also concludes that an army can’t travel more than four days through dessert without resupply, because at that point men and animals will have used up all of the water they can carry.

Much of Persia looks like this, creating obvious supply problems.

Pack animals were not much better at hauling than people, because while they could carry more, they consumed resources at a greater rate than men in proportion. In this era, without shoulder harnesses, horses were apparently harnessed by the neck so that they were choking more the harder they hauled, limiting their utility. In other words, a horse could carry three times as much as a man, but it also eats and drinks three times as much. He concludes that the pack mules of Alexander’s armies were mostly humans, and mostly the actual combat soldiers. The great innovation of Phillip of Macedon, continued by Alexander, was to have soldiers carry their own supplies as much as possible and to greatly limit the baggage train and camp followers. This is what enabled Alexander’s ability to consistently shock his enemies with his lightning marches.

Note that Army size does matter when determining where Alexander resupplied and when and how he split his army. Many areas simply would not have the available forage to supply the army if gathered together in one place, so Alexander often split his army. Seasons are an extremely important factor (obvious but easily forgotten), and Alexander generally organized large troop movements or campaigns to correspond with the time of harvest, when the areas they marched through would have easily extracted food resources.

My Verdict: If you are interested in logistics of ancient armies, this is a short and interesting book that can be dry but is very much worth a read. The author is intelligent and systematic in his analysis. The maps are not detailed enough and are all at the back of the book. Because this entire book is about troop movements, it REALLY needed more maps of better quality within the text itself.

Image Credits:

• Cover image is from Amazon.

• A naval action during the siege of Tyre by Andre Castaigne, 1898-1899; public domain due to age from wiki-commons.

• Final image is shutterstock image of Iranian foothills.