The Peace of Tilsit marked an overthrow for the time of that European settlement and balance of power which had been established five years before by the Peace of Lunéville. The change in his policy had been to a great extent forced on Napoleon; for the league of 1805 had shown that his plan of such a Continental peace as would suffer him to concentrate his whole strength on an invasion of Britain was certain to be foiled by the fears of the Continental states; and that an unquestioned supremacy over Europe was a first condition in the struggle with his great rival. Even with such a supremacy, indeed, his plans for a descent on Britain itself, or for winning the command of the sea which was the necessary preliminary to such a descent, still remained impracticable. The battle of Trafalgar had settled the question of an invasion of England; and a thousand victories on land would not make him master, even for "six hours," of the "silver streak" of sea that barred his path. But Napoleon was far from abandoning his struggle against Britain; on the contrary, he saw in his mastery of Europe the means of giving fresh force and effectiveness to his attack in a quarter where his foe was still vulnerable. It was her wealth that had raised up that European coalition against him which had forced him to break up his camp at Boulogne; and in his mastery of Europe he saw the means of striking at her wealth. His earlier attempt at the enforcement of a "Continental System" had broken down with the failure of the Northern League; but he now saw a yet more effective means of realising his dream. It was this gigantic project which revealed itself as soon as Jena had laid Prussia at his feet. Napoleon was able to find a pretext for his new attack in England's own action. By a violent stretch of her rights as a combatant she had declared the whole coast occupied by France and its allies, from Dantzig to Trieste, to be in a state of blockade. It was impossible to enforce such an order as this, even with the immense force at her disposal; but it was ostensibly to meet this "paper blockade" that Napoleon issued from Berlin, on the twenty-first of November 1806, a decree which--without a single ship to carry it out--placed the British Islands in a state of blockade. All commerce or communication with them was prohibited; all English goods or manufactures found in the territory of France or its allies were declared liable to confiscation; and their harbours were closed, not only against vessels coming from Britain, but against all who had touched at her ports. An army of inspectors spread along the coasts to carry out this decree. [Sidenote: Its results.]