The naval Battle of Portland, or Three Days' Battle took place during 28 February – 2 March 1653 (Gregorian calendar), 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 was killed in a firefight. 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.
- Battle of Portland.
- Brandt, G. (1687).
Het leven en het bedrijf van den Heere Michiel de Ruyter.