It was, however, the second book of _Mare Clausum_ which gave it its chief political importance. It was appropriate and necessary that the claims of Charles should be justified in the domain of law and custom; it was still more necessary that they should be supported by weighty precedents existing in the history of England--that some of his predecessors had been styled Lords of the Sea, and had exercised sovereign jurisdiction over foreigners even on their own coasts. After partially defining the British seas (see p. 19), Selden, as mentioned in a former chapter, labours to show that maritime sovereignty had been continuously exercised within them by the ancient Britons, the Romans, and the Anglo-Saxons in succession, and then by the Norman and later kings. He strove to prove by a multitude of citations from records that the kings of England had perpetually enjoyed exclusive dominion and jurisdiction in the surrounding seas as part of their territory, and were hence styled Lords of the Sea; that they had always preserved the right to forbid fishing and even navigation by foreigners within the British seas, or to exact tribute for that liberty; that the rights of the crown in the seas, asserted both by kings and Parliaments, were in conformity with the common law of England, and had been in several important respects acknowledged by other nations. A great deal of the evidence adduced is, as has been said, irrelevant. The long recital of facts connected with the guarding of the sea, the disposition of fleets, the office and jurisdiction of the admirals, the raising of special taxes--as the Danegeld--for defensive purposes or the equipment of ships of war, might have been paralleled in the records of other maritime states, as France or Flanders.