The Daunting Challenge of Feeding an Ancient Army

Before the advent of modern military logistics like canned goods, supplying armies was a logistical nightmare constrained by harsh realities. Historical records reveal meticulous calculations: one civilian laborer could carry 6 dou (about 40 liters) of grain, while a soldier carried five days’ rations. If one laborer supplied one soldier, provisions lasted 18 days—or just 9 days if accounting for the return journey. Scaling up to three laborers per soldier extended the range to 31 days (16 days with return travel), but this was the absolute limit. For a 100,000-strong army, 30,000 laborers were needed just for food transport, leaving only 70,000 soldiers combat-ready.

These calculations, attributed to the Song Dynasty polymath Shen Kuo, assumed ideal conditions—no accidents, efficient routes, and perfect coordination. In reality, variables like laborer deaths, illnesses, and terrain disruptions made such precision unattainable. Even with 300,000 laborers supporting 70,000 troops, an army moving 40 km daily had a maximum operational radius of 640 km. From Han or Tang Dynasty capitals like Chang’an, this barely reached modern Lanzhou; reaching Ürümqi required 60–70 days.

The Waterway Advantage and Civilizational Limits

Pre-industrial armies relied overwhelmingly on rivers. China’s historical megacities—and military campaigns—clustered along waterways, as bulk transport without ships was unsustainable. Western empires faced identical constraints: Alexander the Great forbade marches exceeding four days from rivers, and Roman legions rarely operated beyond 150 km of the Rhine.

This explains why clashes between distant agrarian powers like Rome and Han China never occurred—neither could project large armies across thousands of kilometers of deserts or steppes. Only nomadic cultures, with their unique adaptations, achieved such feats.

The Nomadic Edge: Mobility and the Humble Sheep

Nomadic empires like the Xiongnu, Mongols, and Turks mastered warfare across Eurasia not through superior weapons, but via an often-overlooked factor: sheep. Unlike agrarian armies, nomads traveled with their food supply—herds that provided milk as a staple and meat as supplemental fare.

Key advantages emerged:
– Living Supply Lines: Sheep converted sparse grassland vegetation into portable nutrition via milk products. A Mongol army’s million sheep could graze 20 square miles daily, eliminating static depots.
– Seasonal Warfare: Campaigns coincided with autumn, when horses were strongest and grasslands lush. Tibetan-Tang wars followed this rhythm, with Tang forces exploiting seasonal retreats.
– Decentralized Logistics: Each warrior’s family herd reduced centralized supply chains. Even Genghis Khan’s early struggles—like hunting small game—reflected milk’s primacy over meat.

The Iron Paradox and Culinary Legacies

Nomadic dependence on sheep also shaped geopolitics. Ming Dynasty restrictions on iron exports to Mongols—especially cauldrons for boiling mutton—turned cookware into status symbols and raid targets. Meanwhile, in Song China, mutton became elite cuisine, with imperial kitchens consuming 350 sheep daily. Poet-officials like Su Shi, exiled and deprived of mutton, famously resorted to roasting discarded bones.

Conclusion: The Silent Architect of History

From Shen Kuo’s calculations to Mongol tactics, logistics dictated the rise and fall of empires more decisively than battles. The sheep’s role underscores a timeless truth: conquest required not just courage, but calories. This hidden history of supply chains reveals why nomadic horsemen, not agrarian superpowers, became antiquity’s greatest conquerors—and how a humble herbivore shaped the world.