Logistics was also affected by the ‘military revolution’ of the early modern period as armies grew in size and technological complexity. The procurement, marshalling and deployment of the human, animal and natural resources necessary to wage war in this new era were daunting. New recruits had to be clothed and trained, and horses bred, broken, fed and transported to the front lines. Saltpetre, charcoal and sulphur needed to be converted into gunpowder; grain ground and baked into bread; raw timber formed into pikestaffs, ship hulls and gun carriages; and hemp woven into rope and canvas. Moreover, to make cannon, copper and tin needed to be mined and smelted into bronze, while ordnance, edged weapons, armour and ships’ fittings required huge supplies of iron ore, fuel and labour. Finally, legions of workers moved earth, timber, mortar and stone to construct a new generation of fortifications (trace italienne) and port facilities. To meet these needs, logisticians wrestled with different ways to best serve the army at home and on campaign.
In the sixteenth century, armies were supplied much as they had been in the Middle Ages, through the use of magazines, supplemented by baggage trains and foraging. But as the size of the early modern army increased, so did the burden of supplying it for war, a burden the rudimentary science of logistics could not keep up with. Unable to provide the ‘umbilical cords’ necessary to supply a large army on campaign in hostile territory, kings and commanders alike sought control of the countryside through the construction or capture of fortresses and fortified outposts. In fact, this inability to consistently supply large numbers of men and horses probably contributed to the rise in the frequency of sieges and an emphasis on positional over manoeuvre warfare.
The changing technological nature of warfare also complicated logistical supply. Not only did commanders have to meet the basic needs of providing bread for tens of thousands of men and fodder for thousands of horses, they also had to resupply stores of gunpowder, and repair or replace small arms and artillery. This often caused a contradiction in supply imperatives. Armies needed to stay close to the fortresses that housed their gunpowder and shot and the ovens that baked their daily bread, while also seeking the forage necessary to keep their horses from starving. And large armies required staggering amounts of food and forage. An army of 30,000 men and 10,000 cavalry horses and 10,000 other horses would consume 45,000 daily rations of bread and 200 tons of dried fodder or 500 tons of green fodder per day.
During the Thirty Years War (1618–1648), supply sank to the level of plunder and pillage as armies operated for years in hostile regions, living off the land with little or no regard for the welfare of non-combatants. Plague and war-related food shortages added to the misery, often killing more people than the actual battles. After mid-century, the rise of stronger centralized states, embodied in Louis XIV’s France, developed the tools and resources necessary to supply larger armies on the march. Unfed or unpaid, early modern armies might evaporate, or worse, turn their anger on the countryside. This reliance on ‘umbilical cord’ supply would continue until the late eighteenth century when the French Revolution and Napoleonic Wars reintroduced the concept of an army foraging for its supplies, thereby, in the words of one recent authority on early modern logistics, ‘liberating it from the tyranny of supply lines’.
Like armies in the medieval period, early modern armies increasingly relied on water transport to supply their needs. Spain, the sixteenth century’s pre-eminent military power, pioneered deep-water maritime technologies and then projected force across the world’s oceans, carving out colonies in the New World and Asia. In Europe, intermarriage and inheritance intertwined Spanish and Habsburg possessions, forcing the Spanish throne to protect its interests in Italy against French encroachment, in the Netherlands against a Protestant revolt, and in central Europe and the eastern Mediterranean against Ottoman expansion.