The conduct of warfare between 1500 and 1700 considerably changed because of the developments in siege warfare, especially with the design of bastions. Artillery, arguably the cause of the new fortifications of towns and cities, does not have as large an impact upon the conduct of warfare, as much as new fortifications did. These new fortifications led to three revolutions in the art of combat: the scale of war increased dramatically, having a wider implication on the running of the state; the art of warfare changed, with new battle tactics introduced, leading to a refurbishment of the army, and their style of war; and fortifications demanded large sums of money to build, thus making warfare far more expensive than in the Middle Ages, changing the mandate of the state to either create war in pursuit of wealth, or to compete with other states as the largest economy. Many historians place different emphasis on where these developments originated, as Roberts believes that it happened in Sweden and the Netherlands, whereas Thompson believes that Spain had a vital role to play. Italy and the Ottoman Empire are also places of disagreement about where the change of nature of warfare originated, however it is clear that no matter where these developments started from, they spread rapidly and had a lasting effect on the nature of warfare. These developments did not come about all at once, but over two centuries, yet with the evolution of military methods and technologies, by 1700, the conduct of warfare was far different to that of the Middle Ages.
Siege warfare against the new style of fortifications, called trace italienne, created a new scale of warfare that hadn’t previously been seen before. Bastions were a response to artillery fire that wreaked havoc upon the medieval style of castle walls, which were intended to repel any climbers, and arrow volleys. The new fortifications were lower and built upon large earthworks that were able to absorb the force of a cannonball. As a result of this, sieges became far more drawn out and to conquer a town, or settlement, more soldiers were required. Parker writes that the result of the, “trace italienne led not only to the predominance of protracted sieges in Western warfare, but also to substantial increases in the size and dramatic changes in the composition of armies,” (Parker, 2009, p. 156) showing the impact of these new fortifications. There became a dilemma of strategy. As previously an army would have sieged a town with a small force in the Middle Ages, from 1500-1700, the size of an army had to increase dramatically, to not only succeed in its primary aim, as, “a heavily defended fortress or town, sheltering perhaps 10,000 men and supported by lesser strongholds in the vicinity, was far too dangerous to be left in the wake of an advancing army: it had to be taken whatever the cost.” (2009, p. 16) However, “if a commander gathered the forces necessary to capture the enemy’s strong places, he risked losing his own.” (Eltis, 1995, p. 92). The cost of battle, as a result of the development of new fortifications became far higher, and yet the result of battles changed too due to the new developments in defence. In the Medieval period, battles were won or lost with a decisive outcome, however with the new scale of warfare in this period, the outcomes were not as obvious as before. Wars became longer, more protracted actions, and cost far more. A contemporary, Roger Boyle, Earl of Orrery, wrote, “Battels do not now decide national quarrels… as formerly… and you will have twenty sieges for one battel.” (Boyle, 1677). The impact of fortifications upon the size and decisiveness of wars was immense, and instead, only civil wars only had a clear outcome as fortifications such as bastions were only used as frontier defences, and civil wars were won through internal battles (Black, 1991). The conduct of warfare as a result of this technological development escalated into something far more than in the previous centuries, and as a result this new scale had an impact on the finance of war, and the economy of Europe. Black argues that this innovation in fortifications, “should be extended back into fifteenth-century Europe when the impetus was the need to face changes in fortifications resulting from the introduction of gunpowder,” (1991, p. 4), which is true to a certain extent, regarding the use of gunpowder, however, there is debate around what century this really took place, because according to the Parker variation of Michael Roberts lecture, “The Military Revolution, 1550-1660,” the revolution actually took place from 1660 onwards, however the first recorded example of bastions being used in 1515 at the Papal port of Civitavecchia. (Eltis, 1995, p. 77) Thus, it is clear that the impact of fortifications upon the scale of warfare was very large, but also that it happened at the beginning of the period 1500-1700, thus, causing a majority of subsequent innovations to have their impact upon the conduct of warfare.
The new types of fortifications had an impact of battle strategy as large forces were required to secure well defended settlements. As a result of the developments in strategy, social division became clearer, and the authority the state had over its population increased. Cavalry had been the ultimate weapon of the Middle Ages, and it was an elite group of noblemen that were allowed to be part of it. However, with the introduction of gunpowder, cavalry became obsolete and Roberts notices the problem of combining missile weapons with close combat. Obsolete against siege warfare, cavalry faded out of importance in military strategy, yet pike-men remained but not for long. Roberts argues that due to the reforms of Maurice of Nassau and Gustav Adolf, who incorporated classical ideas of linear troop set up, instead of squares, like that of the Spanish tercio, signalled a change in the style of warfare. However, Arnold and other historians disagree and show that the Spanish were competent in their military techniques, as they were the only ones to defeat Adolf’s Swedish army. What is clear however, that due to this refurbishment of the army to respond to the changing nature of siege warfare, the role of the infantry became more important than that of the cavalry, opening up the army to all sections of society. Combined with the standardisation of equipment to make training troops economical and the removal of units such as archers which took years to become skilled at, the early modern solider required a certain level of intelligence to be a part of a war machine, instead of an individual. The new infantry, alongside the creation of a standing army, allowed peasants to join up which became a social equaliser, however this did not in fact change the nature of a nation’s class division as the new style of warfare required far more officers. The noblemen took to these positions, granting them more authority over the people than a position in the cavalry ever would have, showing that an impact of new strategy in style of warfare, created a social implication of increasing the class divide. Plus, the new military required monarchs to become involved, and state culture was dictated by military fashion, such as monarch frequenting military uniform rather than civilian. This helped the state have more authority over the people, and this would eventually lead to the idea of conscription. As Thomson writes, “the scale, the costs and the original demands of the new style of warfare are seen to have been the driving forces of coercion-extraction cycle of power and resources that led inexorably to the monopolisation of military force by the central government and to the consolidation of the territorial control of the state.” (Thomson, 1995, p. 273). Thus, through the response to defensive fortifications, a new style of military was required, which impacted the social division across Europe, although not all at once, and increased the control of the state. This shows clearly that through the development of fortifications, although not obviously, the conduct of war drastically changed, as well as the state of society.
Due to the increase in the scale of war, the financing of war shot up, and had a long-term impact that dictated the way many nations interacted with each other, expanding not only the field of war to the land, but also to the sea and to an economic warfare. Unlike Medieval castles that nobles were able to afford to build, the bastions of early modern Europe required a financing far larger than seen before. Many bastions were unable to be completed or abandoned due to the sheer cost, for instance the, “scheme to surround Rome with a belt of eighteen powerful bastions was abandoned in 1542 when the construction of one bastion alone was found to have cost 44,000 ducats (about £10,000).” (Parker, 2009, p. 12). Other plans for bastions had to reduce their number due to cost. However, the defensive advantage of bastions outweighed the price, therefore governments became involved, and what was previously a provincial matter, became national. As the sizes of armies increased, so did the price of the average soldier as standardisation of equipment was introduced. This is significant as the state has more say with the army than previously before, thus having a greater influence over the population. The increase in cost of war changed many motivations for war, as previously war was fought over the squabbles of monarchs, yet with more on the line, international relations became regulated, and more was at stake. Especially with the discovery of the Americas and establishment of colonies over the seventeenth and eighteenth centuries becomes more important, international trade becomes more important, thus expanding the field of war from not only military but to economic warfare. The idea of sanctions and blockades became a legitimate strategy of offense, and as more money is brought into a nation, the more can go to its military. The impact of the scale of war, caused by new types of siege warfare, had a significant impact on a nation’s impetus for war, and changed the conduct of warfare from what was a single field of open combat, both on land and at sea, to a multi-layered system of war, that included political subversion, and economic war.
It is clear that the conduct of warfare changed significantly in the period of 1500 to 1700, for a variety of reasons, however the new style of fortifications, the trace italienne, had the largest impact out of all new innovations and technologies as it would have an impact on all existing aspects of warfare, changing them profoundly. The scale of warfare changed, thus raising the price of war. To combat bastions, new military tactics were required, and allowed for the first modern standing army, that had social repercussions that would arguably lead to the revolutions of the nineteenth century. All these new methods of warfare, or new areas of warfare, would significantly alter the way the European political system worked, as it gave more power to the sovereigns of each state, and created a more organised system of government. The international stage was altered drastically due to the changes in warfare, and arguably, society from 1600 onwards, became far more militarised, inevitably leading to future conflicts, and the power play for the balance of power seen in the eighteenth and nineteenth centuries. Yet, without the introduction of new defences to siege warfare, these innovations would not have come about, or come about as quickly, and therefore, due to the fortifications of settlements, the conduct of warfare was significantly changed more than any other new military method or technology.