The clearest proof of this lies in the annexed orders which Tromp issued on June 20, 1652, immediately before the declaration of war, and after he had had his brush with Blake, in which, if Gibson is to be trusted, Tromp had seen Blake’s line.  From these orders it is clear that the Dutch conception of a naval action was still practically identical with that of Lindsey’s instructions of 1635, that is, mutual support of squadrons or groups, with no trace of a regular battle formation.  In the detailed ‘organisation’ of the fleet each of the three squadrons has its own three flag officers—­that is to say, it was organised, like that of Lord Wimbledon in 1625, in three squadrons and nine sub-squadrons, and was therefore clearly designed for group tactics.  It is on this point alone, if at all, that it can be said to show any advance on the tactics which had obtained throughout the century, or on those which Tromp himself had adopted against Oquendo in 1639.

Yet further proof is to be found in the orders issued by Witte Corneliszoon de With to his captains in October 1652, as commander-in-chief of the Dutch fleet.  In these he very strictly enjoins, as a matter of real importance, ’that they shall all keep close up by the others and as near together as possible, to the end that thereby they may act with united force ... and prevent any isolation or cutting off of ships occurring in time of fight;’ adding ’that it behoved them to stand by and relieve one another loyally, and rescue such as might be hotly attacked.’  This is clearly no more than an amplification of Tromp’s order of the previous June.  It introduces no new principle, and is obviously based on the time-honoured idea of group tactics and mutual support.  It is true that De Jonghe, the learned historian of the Dutch navy, regards it as conclusive that the line was then in use by the Dutch, because, as he says, several Dutch captains, after the next action, were found guilty and condemned for not having observed their instructions.  But really there is nothing in it from which a line can be inferred.  It is all explained on the theory of groups.  And in spite of De Jonghe’s deep research and his anxiety to show that the line was practised by his countrymen as well as by the English in the first Dutch War, he is quite unable to produce any orders like the English instructions of 1653, in which a line formation is clearly laid down.

But whether or not we can accept De Jonghe’s conclusions as to the time the line was introduced into the Dutch service, one thing is clear enough—­that he never ventured to suggest that the English copied the idea from his own countrymen.  It is evident that he found nothing either in the Dutch archives or elsewhere even to raise such an idea in his mind.  But, on the other hand, his conspicuous impartiality leads him to give abundant testimony that throughout these wars thoughtful Dutch officers were continually praising the order and precision of the English tactics,