Battle of Portland The naval Battle of Portland , or Three Days ' Battle took place during 28 February - 2 March 1653 ( New style ) , during the First Anglo - Dutch War , when the fleet of the Commonwealth of England under General at Sea Robert Blake was attacked by a fleet of the Dutch Republic under Lieutenant - Admiral Maarten Tromp escorting merchant shipping through the English Channel . The battle failed to settle supremacy of the English Channel , although both sides claimed victory , and ultimate control over the Channel would only be decided at the Battle of the Gabbard which allowed the English to blockade the Dutch coast until the Battle of Scheveningen , where Admiral Maarten Tromp would meet his fate at the hands of an English musket ball . As such , it can be considered a slight setback for the English nation and another example of Dutch superiority regarding pure seamanship at the time . It also illustrated England ' s drive to control the seas , which would ultimately allow it to become the prime maritime power of the world . Background . The First Anglo - Dutch War was caused by friction between the two naval powers of the century , competing for strategic supremacy over the world ' s merchant routes . England and the United Provinces had always been ' natural allies ' against the Habsburgs , as deemed by the Council of State under the rule of Charles I . It has been argued that had Charles I stayed in power the war between the two nations would have never sprung , as he would never have obtained the necessary funding from parliament . However , the rise of the English Parliament under Oliver Cromwell saw the deterioration of diplomacy between the two as the Dutch stadtholder financially supported the Royalists . During the English Civil War , the Dutch had taken advantage of the internal strife within their neighbours , and greatly expanded their maritime presence throughout the world ' s merchant harbors and routes , ultimately even challenging British dominance in its colonies , and the Dutch even boasted of driving all nations out of the sea . Nonetheless , Cromwell did not challenge the Dutch , still consolidating his power at home . This changed when Parliamentary armies finally routed the Royalists at the Battle of Worcester , effectively ending the English Civil War . With Cromwell fully in power , the Parliament passed the Navigation Act of 1651 , requiring all goods destined to English ports to be transported by English ships , which severed part of the Dutch ability to trade , since they were cut off from all of England ' s colonies in the Americas and elsewhere . Later that year the Parliament gave an order which allowed English privateer s and warships to seize Dutch shipping and ' recover their losses ' from Dutch vessels . Finally , the English Parliament began to enforce its sovereignty over the " British Seas " , which granted the English Navy dominion from the North Sea to Cape Finisterre . The translation of Parliament ' s words into action came when English Admiral Sir George Ayscue claimed Barbados as part of the Commonwealth and seized 27 Dutch ships . The Dutch response was divided ; the moderate States of Holland tried to appease the English ; but when the negotiations failed and the Navigation Acts were adopted the ferocious Orangist faction became more powerful , and the States General passed a resolution which would allow the Dutch war fleet , to be tripled in size , to protect Dutch interest over the areas in question . This fleet was put under the command of Admiral Maarten Tromp , who had defeated the sixth and final Spanish Armada at the Battle of the Downs , 31 October 1639 . That same year , the Dutch signed a treaty with Denmark with the intent to hurt English shipping . War finally broke out after a confrontation between admirals Robert Blake and Maarten Tromp , May 1652 , at the Battle of Dover . Minor skirmishes followed at the Battle of Plymouth , the Battle of Elba , and the Battle of Kentish Knock . The two fleets met for the first time in a major battle at the Battle of Dungeness , November 1652 . The battle turned out to be a heavy English defeat , forcing the English to rethink their naval strategy , led by Admiral Sir Henry Vane and an Admiralty Committee , including developing a tactic that would mark naval warfare for the following century . Taking a page out of the Dutch book the English reorganised each fleet into squadrons for greater tactical control . In fact , the tactic , renamed the line - of - battle tactic , would remain key to English / British naval strategy until the end of the Second World War . The two fleets would meet again off Portland . Battle . During the first days of February 1653 , Tromp escorted a convoy of merchant ships through the Channel and put them safely into the Atlantic Ocean . He set to return to his home port , but first anchored off La Rochelle to repair and resupply his ships and waited for expected merchantmen coming from the Atlantic . He attempted to set sail on 20 February with 152 merchantmen , but was held back for three days by high winds and rough seas . On 24 February Tromp finally set sail , entering the area off Portland four days later where he spotted Blake ' s fleet attempting to cut them off . Immediately , Tromp set the signal for a general attack and began the offensive with the wind in his favor as he had the weather gauge . Tromp ' s flagship , " Brederode " , met Blake ' s flagship , " Triumph " , immediately , sending a broadside at mere metres distance . Turning around , without having received a response from English gunners , he put a second broadside in " Triumph ' s " other side , and finally then delivered a third after turning around again . Blake subsequently veered away and decided to fight at long range . Dutch Commodore De Ruyter was able to attack the English rear and engaged the largest English vessel in the fleet , " Prosperity " , ending in a boarding attempt which was repulsed by the crew of the British vessel the first time around . A second boarding attempt forced the " Prosperity " to surrender thereafter , however . An attempt to reclaim the ship surrounded De Ruyter , but after an intense fight the Dutch commodore was able to fight his way out . The battle continued for the day with heavy fire exchanged by both sides . Later on 28 February Blake sent a squadron of frigates to intercept and claim the Dutch merchantmen off the coast of La Rochelle . Tromp quickly responded by sending his own captains to intercept the English . Nonetheless , night brought a close to the day ' s battle . The following day the English were the first to begin the engagement , with the wind in their favor . The initiative of the English fleet was not gone from the previous day , but five attempts failed to break the Dutch line . The day also saw 12 Dutch merchantmen caught by Blake ' s frigates after attempting to make a run for it , against Tromp ' s explicit orders . After the second day most of the Dutch warships were out of powder and shot , and there was none to resupply with . The third day ended just the same , with a failure to break the Dutch line . Several Dutch captains attempted to flee after completely running out of ammunition but Tromp ended their flight with a few shots across their ships . The battle ended for the day when Blake drew off , after forcing the Dutch to fight to the point where they only had around half an hour worth of shot left . Blake ' s reasoning for the disengagement has been attributed to the fact that he received a wound to the thigh that day . On the fourth day the English again attempted to resume action , but they found the sea empty of Dutch warships . Tromp had guided the remainder of his fleet along the coastline , escaping certain defeat the next day , leaving eight warships and a number of merchantmen behind . Although both sides claimed victory after the battle , the fact remains that it was Tromp who left the field , not Blake , and in the end , it was Blake who was able to commandeer 20 to 40 Dutch merchantmen and at least eight Dutch warships back to his homeport . Aftermath . The Battle of Portland restored English dominance over the English Channel . While Dutch propaganda tried to paint the battle as a Dutch victory or a " glorious defeat " and the populace publicly rejoiced at the heroism shown , Admiral Tromp and the other flag officers knew better , all coming home in an extremely dark mood . They concluded that the adoption of line tactics by the English would make it impossible for the Dutch to compensate inferior firepower with better seamanship and they urged the States - General to finally start building real heavy warships instead of replacing losses by recruiting armed merchants . In a desperate attempt to at least keep the North Sea open , an under - equipped Dutch fleet engaged the English again at the Battle of the Gabbard .