The truce of 1609 which for the time being terminated Spain's attempts to reconquer the northern Netherlands was in fact a defeat of the southern Netherlands, although the Archduke Albert and his principal minister Spinola had done so much to bring it about. It was a defeat because until further notice the independence of the rebel provinces was recognized and the split in the seventeen provinces confirmed. The period now starting is indeed one of growing estrangement between the two parts of the old Burgundian state. In 1609 the northern republic had not yet reached its full territorial extent. The parts of Brabant, Limburg and Flanders which were finally to belong to it were conquered only after 1621. But in principle this northern state was already by 1609 what it continued to be until the French Revolution. Already in these early years of the seventeenth century it was getting used to its status of sovereign independence and was adopting the character of a nation. In the southern provinces a parallel development took place. Religious, social, economic and political contrasts seemed inevitably to lead to the growth of two different, indeed hostile national feelings.

This should not, of course, be exaggerated. The national factor did not yet possess much influence. Far more important was religion. When studying the attitude of the Jesuits who had such a predominant importance in the history of the southern Netherlands and of the Calvinists in the north who had comparatively much less influence but nevertheless set their seal upon Dutch political and social life, it is evident that both these groups in this period had not yet given up the idea that the north and south fundamentally formed a unity; they even sought to restore it.