Starting in the late sixteenth century armies in Europe greatly increased in size, upwards of 100,000 or more in some cases. This increase in size came not just in the number of actual soldiers but also camp followers - anywhere from half to one and a half the size of the army itself - and the size of the baggage train - averaging one wagon for every fifteen men.[3] However very little state support was provided to these massive armies, the vast majority of which consisted of mercenaries. Beyond being paid for their service by the state, an act which bankrupted even the Spanish Empire on several occasions, these soldiers and their commanders were forced to provide everything for themselves. If permanently assigned to a town or city with a working marketplace, or traveling along a well-established military route, supplies could be easily bought locally with intendants overseeing the exchanges. In other cases an army traveling in friendly territory could expect to be followed by sutlers, although their supply stocks were small and subject to price gouging, or a commissioner could be sent ahead to a town to make arraignments, including quartering if necessary.[4]
When operating in enemy territory an army was forced to plunder the local countryside for supplies, a historical tradition meant to allow war to be conducted at the enemy's expense. However with the increase in army sizes this reliance on plunder became a major problem, as many decisions regarding where an army could move or fight were made based not on strategic objectives but whether a given area was capable of supporting the soldiers' needs. Sieges in particular were affected by this, both for any army attempting to lay siege to a location or coming to its relief. Unless a military commander was able to implement some sort of regular resupply a fortress or town with a devastated countryside could be effectively immune to either operation.[4]
Conversely armies of this time had little need to maintain lines of communication while on the move, except insofar as it was necessary to recruit more soldiers, and thus could not be cut off from non-existent supply bases. Although this theoretically granted armies freedom of movement the need for plunder prevented any sort of sustained, purposeful advance. Many armies were further restricted to following waterways due to the fact that what supplies they were forced to carry could be more easily transported by boat. Artillery in particular was reliant of this method of travel, since even a modest number of cannons required hundreds of horses to pull overland and traveled at half the speed of the rest of the army.[