Nevertheless, Boroughs’ work was the first successful attempt to bring together a great array of historical facts in favour of the English claims to the dominion of the seas. Like Selden, he begins with the Roman occupation of Britain in order to show that from the first the “British nation had the supreme power of command of their own seas”; and, moreover, he gives all the more important documents to be found in _Mare Clausum_,--the ordinance of John, the rolls of Edward I. and Edward III., the charter of Edgar, the Laws of Oleron, commissions to the admirals, safe-conducts, and extracts from the Burgundy treaties. He is very emphatic as to the king’s right to the dominion of the seas and the fisheries. “That princes,” he says, “may have an exclusive property in the soveraigntie of the severall parts of the sea, and in the navigation, fishing and shores thereof, is so evidently true by way of fact, as no man that is not desperately impudent can deny it”; and--no doubt for the benefit of the Dutch--he adds that “if any nation usurp our rights, the king has a good sword to defend them.” He asserts that the kings of England in succession had the “sovereign guard” of the seas; had imposed taxes and tributes upon all ships navigating or fishing in them; and had closed and opened the passage through them to strangers, as they saw cause. The sovereignty of the sea he calls “the most precious jewel of his Majesty’s crown, next (after God) the principal means of our wealth and safety.” A considerable part of the treatise is taken up with the fisheries, the information being almost wholly derived from previous writers; the usual comparisons are drawn of the flourishing state of the fisheries of Holland and the poor condition of those of England, and the usual statements made as to the benefits that would accrue to the kingdom if the fisheries were developed. Boroughs’ treatise, however interesting from the historical documents it contained, had serious defects when considered as a formal justification to Europe of the policy of Charles. The facts were not skilfully marshalled; the deductions were bald and crude; and above all, it was destitute of arguments and reasoning founded on law. Grotius was then the Swedish ambassador at Paris, his works were well known and esteemed throughout Europe, and it would have been indiscreet to attempt to answer his elaborate arguments against such claims to _mare clausum_ by saying that these claims were self-evident and that only an impudent person would deny them.