The situation was such that an armed collision was almost certain to happen with such an admiral as Tromp in command.  It came suddenly through a misunderstanding.  The Dutch admiral while cruising past Dover met, on May 29, fifteen English ships under Blake.  The latter fired a warning shot across the bows of Tromp’s ship to signify that the flag should be struck.  Tromp declared that he had given orders to strike the flag, but that Blake again fired before there was time to carry them out.  Be this as it may, the two fleets were soon engaged in a regular fight, and, the English being reinforced, Tromp withdrew at nightfall to the French coast, having lost two ships.  Great was the anger aroused in England, where the Dutch were universally regarded as the aggressors.  In the Netherlands, where the peace party was strong, many were disposed to blame Tromp despite his protests.  Adrian Pauw himself left hastily for London, John de Witt being appointed to act as his deputy during his absence.  Pauw’s strenuous efforts however to maintain peace were all in vain, despite the strong leanings of Cromwell towards a peaceful solution.  But popular feeling on both sides was now aroused.  The States-General, fearing that the Orangists would stir up a revolt, if humiliating terms were submitted to, stiffened their attitude.  The result was that the envoys left London on June 30, 1652; and war was declared.

The Dutch statesmen who sought to avoid hostilities were right.  All the advantages were on the side of their enemies.  The Dutch merchant-fleets covered the seas, and the welfare of the land depended on commerce.  The English had little to lose commercially.  Their war-fleet too, though inferior in the number of ships, was superior in almost all other respects.  The Stuarts had devoted great attention to the fleet and would have done more but for lack of means.  Charles’ much abused ship-money was employed by him for the creation of the first English professional navy.  It had been largely increased by the Parliament after 1648; and its “generals,” Blake, Penn and Ayscue, had already acquired much valuable experience in their encounters with the royalist squadron under Prince Rupert, and in long cruises to the West Indies for the purpose of forcing the English colonies to acknowledge parliamentary rule.  The crews therefore were well trained, and the ships were larger, stronger and better armed than those of the Dutch.  The position of England, lying as it did athwart the routes by which the Dutch merchant-fleets must sail, was a great advantage.  Even more important was the advantage of having a central control, whereas in the Netherlands there were five distinct Boards of Admiralty, to some extent jealous of each other, and now lacking the supreme direction of an admiral-general.