IN historical studies, the term ‘sea power’ – meaning control over the sea – is usually connected with the work of the American naval officer A. T. Mahan. He established the principle that the sea could only be brought under control through the domination of the enemy's naval forces. According to Mahan this could only be realised in sea battles, and, if necessary, by blockades combined with the threat of an attack. The greatest care should to be exercised with regard to Mahan's concepts of sea power in the period preceding the one on which he based his conclusions. The danger has not discouraged historians from finding inspiration in his ideas on sea power.

The present paper seeks to contribute to the debate about the relevance of Mahan's concept of sea power for the early modern period by studying the case of the Habsburg Netherlands. Although the Netherlands were not engaged in any major sea battle during the first half of the sixteenth century a certain notion of sea power does seem to have played a role in naval strategic thinking. It will be argued that naval superiority alone over enemy forces did not ensure the exercise of sea power. After all, merchant ships played an important role in naval warfare well into the seventeenth century. Therefore the total seagoing merchant fleet of a town, region or country – the maritime potential – had to be taken into account when considering its sea power.