Three Hundred and Thirty Five Years' War

The Three Hundred and Thirty Five Years' War (Driehonderdvijfendertigjarige Oorlog) was a theoretical state of war between the Netherlands and the Isles of Scilly (located off the southwest coast of Great Britain). It is said to have been extended by the lack of a peace treaty for 335 years without a single shot being fired, which would make it one of the world's longest wars and a bloodless war. Despite the uncertain validity of the declaration of war, and thus uncertainty about whether or not a state of war ever actually existed in the first place, peace was finally declared in 1986, bringing an end to any hypothetical war that may have been legally considered to exist.

Origins
The origins of the war can be found in the Second English Civil War, fought between the Royalists and Parliamentarians from 1642 to 1652. Oliver Cromwell had fought the Royalists to the edges of the Kingdom of England. In the West of England this meant that Cornwall was the last Royalist stronghold. In 1648, Cromwell pushed on until mainland Cornwall was in the hands of the Parliamentarians.

The Royalist Navy was forced to retreat to the Isles of Scilly, which lie off the Cornish coast and were under the ownership of Royalist John Grenville

Dutch Navy alliance
The navy of the United Provinces of the Netherlands was allied with the Parliamentarians. The Netherlands had been assisted by the English under a number of rulers in the Eighty Years' War (1568–1648), starting with Queen Elizabeth I of England. The Treaty of Münster (30 January 1648) had confirmed Dutch independence from Spain. The Netherlands sought to maintain their alliance with England and had chosen to ally with the side likely to win the Civil War.

The Dutch Navy was suffering heavy losses from the Royalist fleet based in Scilly. On 30 March 1651, Admiral Maarten Harpertszoon Tromp arrived in Scilly to demand reparation from the Royalist fleet for the Dutch ships and goods taken by them.

According to Whitelocke's Memorials (cited in Bowley, 2001), 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".

As most of England was now in Parliamentarian hands, war was declared specifically upon the Isles of Scilly.

Royalist surrender
In June 1651, soon after the declaration of war, the Parliamentarian forces under Admiral Robert Blake forced the Royalist fleet to surrender. The Netherlands fleet, no longer under threat, left without firing a shot. Due to the obscurity of one nation's declaration of war against a small part of another, the Dutch did not officially declare peace.

Peace treaty
In 1985, Roy Duncan, historian and Chairman of the Isles of Scilly Council, wrote to the Dutch Embassy in London to dispose of the myth that the islands were still at war. Embassy staff found the myth to be accurate and Duncan invited the Dutch ambassador Jhr. Rein Huydecoper to visit the islands and sign a peace treaty. Peace was declared on 17 April 1986, 335 years after the "war" began. The Ambassador joked that it must have been harrowing to the Scillonians "to know we could have attacked at any moment."

Authenticity
Bowley (2001) argues that the letter in Whitelock's Memorials is the probable origin of the "declaring war" legend: "Tromp had no 'Commission' from his government to declare war on the rebels in Scilly; but he did come to try—by a show of force, threats and even by violence perhaps, although this never happened—to seek reparation for Royalist piracies, but short of resorting to any action which might offend the Commonwealth. ... even if [a war] had occurred in 1651, all matters pertaining would have been resolved in 1654 as a part of the treaty between England and the United Provinces at the end of the First Dutch War".