Naval war between England and Holland, caused by commercial maritime competition, particularly in the East Indies. The build up to the war included the passing of the First Navigation Act (9 October 1651), which forbade the import of goods unless transported either in English vessels or by vessels from the country of origin, a measure aimed against the Dutch. The first fighting took place on 19 May 1652 off Dover, where a 20 strong English fleet under Admiral Robert Blake attempted to search a Dutch fleet under Admiral Maarten Tromp (battle of Goodwin Sands).
War was declared in July, and the first major battle followed on 28 September 1652. The battle of Kentish Knock saw an English fleet of 60 ships under Blake defeat a similar Dutch Fleet under Cornelius de Witt, after which Tromp was restored to command of the Dutch fleet, and on 30 November, with 80 ships, inflicted a severe defeat on a 40 ship strong English fleet under Blake at the battle of Dungeness. From this point the war turned towards the English. On 18 February, a running fight began after the English fleet stalked a Dutch convoy, which led to the battle of Portland or Beachy Head (20 February), in which Tromp lost 17 men-at-war and over 50 merchant ships from the convoy, while the English only lost 10 ships, although Blake was wounded. March 1653 saw the first issuance of the Fighting Instructions, which laid out the foundation of English Naval tactics for over a century, and insisted on line-ahead formation, with the ships following each other with only a 100 yard gap, intended to make the best use of the broadside. The Instructions saw their first test at the battle of the Gabbard Bank (2-3 June 1653), where the arrival of Blake with reinforcements caused the Dutch to retreat with 20 losses. From June-July 1653 the English fleet blockaded the Dutch coast, until on 25 July Tromp was able to get past the blockade. The decisive battle of the war followed. On 31 July 1653 the battle of Scheveninghen (or Texel) was fought between a combined Dutch fleet numbering 100 ships, and an equally sized English fleet under George Monck. In a twelve hour fight, the Dutch lost 30 men-at-war, 1,600 sailors, and Admiral Tromp, who was killed in the fighting. English losses were half that, and the battle marked then end of serious fighting in the war. The war was finally ended by the Treaty of Westminster (3 April 1654), in which Holland agreed to compensate England, and to respect the Navigation Act.