As we have seen, many of the innovations of the Military Revolution could not be exported, or looked completely different outside Europe. However, some specifically European military innovations, like the warship, did not lose relevance in Asia. Another one of these was European fortress design.
Back in Europe, as a response to the advent of artillery, the design of fortresses had evolved from the form which we would associate with a medieval castle, to an almost scientific design by the end of the 16th century. High, massive stone walls, an easy and grateful target for artillery, were gradually replaced with lower, sloping earthen walls covered with a layer of stone, which absorbed the shock of an impact and would not collapse. The simple rectangular castle designs with round corner pavilions of the early renaissance were gradually replaced by ever more complicated geometrical designs, which did not leave a single angle where the defending artillery could not reach. Whereas at the end of the 15th century, no city wall or fort could withstand the onslaught of the artillery trains brought along by the armies of those European states that could afford them, the 16th century saw the evolution of a defensive answer to the development of artillery. By the dawn of the 17th century, these defensive innovations had advanced to such a point that taking a city or a fortress could no longer be achieved by artillery bombardment, but (once again) involved laying siege to a city, starving it rather than taking it by force.
At the beginning of this 17th century, the Netherlands were the avant-garde of artillery fortress design. The wars with Spain had given the Dutch quite some experience with these fortresses, and had also moved the rulers of the newborn Dutch Republic to invest in training and study of fortress building at Dutch universities. The Dutch Republic had become a centre of expertise on the matter. Designers like Simon Stevin became the European authority on fortress design, and engineers came to the Dutch Republic from across Europe to learn the secrets of the trade.
As European rivalry in the Asian waters started, an arms race with regard to fortifications immediately took off. The greatest threat for European settlements in Asia, invariably placed along the coast or a river mouth, was artillery bombardment from other Europeans’ sailing vessels. The appearance of Dutch and English ships in Asian waters was therefore a good incentive for the Iberian powers to seriously review the defences of their settlements. Until then, their defences would mainly have had to protect their settlements from land attacks by Asian powers, and were therefore of cheaper designs, with vertical walls and often round corner pavilions. The prospect of European ships, armed with several dozens of cannon each, appearing before the walls of these fortresses on the seaside, made the Portuguese and Spaniards invest in updating their fortifications and founding more cannon.
The Company, meanwhile, also built its settlements with an eye on possible attack by other European parties. The fortress that the Europeans built on Banda, as discussed above, was the first fortress actually built instead of conquered by the VOC, and its aim of defending the islands against other European parties is clear in its design, which, although humble in setup, follows the European state of the art with regard to fortress building. Batavia, initially defended with some cannon on the two reinforced warehouses that were there before Coen conquered the area for the Company, was defended with a provisional system of motes and bastions, until a huge and costly fortress was built in the years between 1631 and 1639, designed to withstand any European attack. As, in the years following 1636, the Company conquered various Portuguese fortresses, it usually deemed the existing defences insufficient. It would make the fortresses smaller so that it needed fewer soldiers to defend them, and also updated the defences to the European standard of the time. While in Europe, fortress building had become a highly scientific and specialized profession, the VOC did not hire such specialists for its fortresses: the designs were made by the city architects of larger VOC settlements such as Cape Town, Batavia or Colombo. These made use of the methods and handbooks that had been developed by Simon Stevin and his contemporaries, which provided standardized plans for fortresses. These merely needed to be adapted to local circumstances.
These fortresses, while designed for European forms of warfare, also proved highly effective against local powers. In the entire history of the VOC, only two fortresses were ever conquered by a non-European party: Fort Zeelandia on Formosa, facing a professional Chinese army, 25.000 strong, had the flaw of having a hill overlooking the fortress, defended by only a small redoubt. After a siege of nine months, this small redoubt was taken, bringing the inner fortress both in sight and in range of Chinese artillery. Zeelandia surrendered one week later. The other fort the VOC lost to a non-European party was a small fort called Rembang on Java, taken in 1741, after its commander had lost his mind, was facing a mutiny of his own troops and simply surrendered the place to the Javanese. These, however, were the notable exceptions, and much more representative of the worth of European defences are perhaps the 1628 and 1629 attacks of Mataram armies against the provisional yet European-style defences of Batavia. Although in the first year, Mataram brought 10.000 men under the walls of Batavia, and at least double that number the next year, the city held out. In practice we see that it was already quite extraordinary for an Asian power to even attack a European artillery fortress: most did not even bother to try.
The fact that European-style fortresses turned out to be virtually unconquerable had far-reaching implications for the functioning of the Company as a whole. Firstly: it was an essential element in the longevity, the permanence of the VOC discussed above. Whereas VOC fortresses were usually citadels, with the better part of the city outside their walls, the warehouses and the administration were always inside the fortress. Thus, the VOC’s political institutions, chain of command, trade and flow of information could not be permanently disrupted or destroyed by any local power. This ‘physical’ aspect of the VOC’s permanence and its political aspect mutually reinforced each other. Secondly, VOC fortresses were also an important factor in the VOC’s maritime hegemony, as fortresses did not only protect a settlement or city, but could also control a sea-lane or serve as a base of operation for fleets. In the course of the early seventeenth century, we see that the VOC grew interested in certain geostrategical goals. We see this exemplified in the fact that one of the main reasons for conquering the Malabar Coast was to make sure that no other European power would use it as a base of operations from where to conquer Ceylon. Another example is the protracted siege of A Famosa, the huge Portuguese fortress in Malakka, from 1636 to 1641. The VOC dedicated an enormous amount of resources to the siege of this fortress, not just to get hold of the trade there, but because A Famosa controlled the Malakka Strait. As fortress Batavia already controlled the Java Strait, this was essentially an attempt to monopolize access to the South Chinese Sea from the west. In this manner, seaboard European artillery fortresses combined with superior warships, gave the VOC its maritime hegemony over local powers, and increasingly over other European parties as well.
There has been ample discussion on the quality of European fortresses compared to local fortresses, and how the latter changed in the light of the arrival of Europeans. Particularly for the case of Southeast Asia, opinions on the matter vary enormously, as some hold it that fortress-building was virtually non-existent in Southeast Asia, where notions of territory were of less importance, and only made its first hesitating steps in response to European methods of war. Other authors, however, do not only claim that there was in fact a tradition of fortress building in Southeast Asia, but that these fortresses were in no way inferior to European ones. The latter statement is absolutely not borne out by the facts, as the evidence of these same authors brings to the fore that Southeast Asian fortresses were usually square buildings, more often made out of wood than out of stone. We also need to consider the fact that whereas Rembang was the only fortress the VOC ever lost to a Southeast Asian party, the Javanese Wars saw the conquest of dozens of Javanese fortresses by VOC troops. The fact that the authors making these claims never make any argumented comparison and only talk about Southeast Asian forts, suggests that their idea of European fortress building is somewhat underinformed.
Be all of this as it may: there is no doubt that the arrival of Europeans was indeed answered by Asian initiatives in the field of fortifications. The most famous case of how Asian fortifications were influenced by innovations from Europe, is to be found in the Japanese civil wars. Here, various European innovations in the field of warfare were copied and even surpassed, among which fortress building. When cannon, both imported and locally produced, started playing an increasingly important role in these wars around 1580, this soon triggered a response in fortress building, just as it had done in Europe. The resulting fortresses, such as Kumamoto and Osaka castle, showed a striking resemblance with European artillery fortresses: they had sloping walls, and the outlay of the walls was designed to leave no dead angles and provide flanking fire. Nonetheless it is uncertain whether these innovations were directly copied from European examples: it is as likely that the Japanese, confronted with the same problems posed by the rise of artillery (which the Japanese did copy from the Portuguese) came up with very similar solutions.
In other cases, European influence on the defences of Asian powers was a lot more direct, the most telling case probably being the defences of Makassar. Being the capital and harbour of Gowa, the main rivalling sea power as well as biggest trade competitor to the VOC in the Archipelago, Makassar housed various trade diasporas from all over Asia, as well as English, Danes and a large number of Portuguese. Europeans were involved in aiding and advising the king with regard to his defences: a Dutch travel account of 1632 tells us how the king’s ordnance was managed by an Englishman who had converted to Islam. Apparently already expecting trouble with the VOC, the resident Portuguese and the king thought it in their mutual benefit to aid each other in building up the city’s defences. In the 1630s, a European-style fortress called Sombaopu was erected at the capital, which in the following decades was supplemented with a system of redoubts, and eventually the city’s entire coastline was sealed off by a brick wall, eleven kilometres long. When it finally came to blows with the VOC in the 1660s, a good portion of the artillery that defended the city was operated by Portuguese, as Wouter Schouten informs us in his account of the events.
These Makassarese defences, born out of the cooperation of various parties which saw a common enemy in the Dutch, was one of the greatest military challenges that the VOC ever faced. When in 1666 the VOC decided to launch another expedition against the kingdom, the commander Cornelis Speelman was specifically instructed to limit the use of European soldiers and have the allies do all the fighting, as well as not to directly attack the capital but to limit himself to raiding the coast in several locations. The Company was apparently afraid to directly confront the Makassarese defences. When the ranks of Speelman’s allies grew and he decided to go against the capital on his own initiative in the beginning of 1667, the fleet wasted all its ammunition upon the defences without any result. A long siege ensued, which ultimately lasted for a good 2½ years. Only through sapping did Speelman’s troops eventually breach the walls of the fortress.