The Netherlands sought to maintain their alliance with England and had chosen to ally with the Parliamentarians as the side likely to win the Civil War.

On 30 March 1651, Lieutenant-Admiral Maarten Harpertszoon Tromp arrived in Scilly to demand reparation from the Royalist fleet for the Dutch ships and goods taken by them.

[2] According to Whitelocke's Memorials, a letter of 17 April 1651 explains: "Tromp came to Pendennis and related that he had been to Scilly to demand reparation for the Dutch ships and goods taken by them; and receiving no satisfactory answer, he had, according to his Commission, declared war on them."

[4] In 1986, Roy Duncan, historian and Chairman of the Isles of Scilly Council, decided to investigate and wrote to the Dutch Embassy in London.

Embassy staff found that no peace treaty had ever been signed, and Duncan invited the Dutch ambassador Jonkheer Rein Huydecoper to visit the islands and officially end the "conflict".

In his book Loose Cannons: 101 Myths, Mishaps and Misadventurers of Military History he argues that no such war could have existed because neither side was sovereign: "Tromp was an admiral, not a nation, and Scilly part of England".