The cause of the quarrel was the Navigation Act, passed by England for the express purpose of building up the English commercial marine at the expense of the Dutch. The latter were then the world’s carriers on the ocean. They derived an immense profit from carrying the goods of other countries, in their own bottoms, from these other countries to England. The Navigation Act forbade this, allowing only English bottoms to be used to carry goods to England, unless the goods were carried in the ships of the country from which they came. This is the kind of measure especially condemned by the _laissez-faire_ school of economists, and its good results in this case have always puzzled them; while, on the other hand, its success under one set of conditions has been often ignorantly held to justify its application under entirely different conditions. In other words, like the system of protective tariffs, it is one of those economic measures which may or may not be useful to a country, according to changes in time and circumstances. In the Cromwellian period it benefited the English as much as it hurt the Dutch, and laid the foundation of English commercial supremacy. Another cause of war was the insistance by the English upon their right to have their flag saluted by the Dutch as well as by other foreign powers. There followed a bloody and obstinate struggle for the mastery of the seas. Battle after battle was fought between the Dutch and English fleets. The latter were commanded by Blake, Monk, Dean, and other officers, who had won distinction ashore—for the process of differentiation between military service on land and on the sea was far from complete. The fighting was most determined, and the Dutch won two or three victories; but they were defeated again and again, until finally beaten into submission. The war was one undertaken purely from motives of commercial greed, against the nation which, among all the nations of continental Europe, stood closest to England in religious belief, in form of government, in social ideas, and in its system of political liberty. Cromwell hated the thought of the two free Protestant powers battling one another to exhaustion, while every ecclesiastical and political tyranny looked on with a grin of approbation. He wished the alliance, not the enmity, of Holland; and though, when the war was once on, he and those he represented refused in any way to embarrass their own government, yet they were anxious for peace. The Parliament, on the other hand, hailed the rise of the Navy under Blake as a counterpoise to the power of the army under Cromwell. One effect of this Dutch War was to postpone the question of the dissolution of Parliament; another, to cause increased taxation, which was met by levying on the estates of the Royalist Delinquents, so-called. [Illustration: Admiral Robert Blake. From the portrait at Wadham College, Oxford. By permission of the Master of Wadham. ]