The last fifty years of the seventeenth century were so eventful and saw such alterations in the outward appearance of western and central European life that prima facie this may be regarded as a significant period in the development of social classes and in the related development of institutions. This presumption may be tested by tracing some of the major changes and their connections, and it will be convenient to begin with the most obvious, the changes in the social aspects of war. It has been written, and it may be accepted as established, that from somewhere about 1560 to somewhere about 1660 Europe underwent a ‘military revolution’. Armament, tactics and strategy had changed. They now required new kinds of discipline, a new organisation of fleets and standing armies, new and more intensive applications of technical and general knowledge. The financial and administrative machinery of supply, the systems of political control and the social composition of the armed forces were all remodelled.

The effects of the military revolution were shown by a salient fact of social history: armies and fleets were much larger than before. Leaving out of account the armies of the Turks, we may say that the largest force ever previously united under a single command had been the 175,000 men under the orders of Gustavus Adolphus in 1632, but this was a momentary combination which was not maintained, whereas, in his navy and his army, Louis XIV kept more than double that number in service for years together. There were some countries, such as Spain, which were unable to enrol as many men as they had done before; but there were new military powers, such as Brandenburg-Prussia, which had 2000 men after it made peace in 1640 and 30,000 when it was at peace in 1688.