The Fourth Anglo-Dutch War (1780–1784) was a conflict between the Kingdom of Great Britain and the Dutch Republic. The war, motivated by imperial competition, was a disaster for the Netherlands, whose republic was reduced to a Prussian puppet.
As well as being the fourth and last in a series of Anglo-Dutch Wars, it is also considered as being part of the wider American War of Independence.
The government tried to resolve internal conflicts by uniting the people against a common enemy. Though Great Britain and the Republic had been allies since the Glorious Revolution of 1688, the Dutch had become very much the junior partner in the alliance, and had slowly lost their erstwhile dominance of world trade to the British. London had replaced Amsterdam as the world's leading financial capital. This led to resentment and so Britain was the ideal scapegoat, especially as the patriots were largely pro-French.
Initially the British considered the Dutch allies in their attempt to stamp out the rebellion in their American colonies. They unsuccessfully attempted to hire Dutch soldiers for use in the Americas, in a similar manner to the Hessian and Brunswicker contingents they hired and deployed. There had been a long-standing alliance between the British and Dutch that had lasted a century, and there was a widespread fear amongst the major European colonial powers of similar rebellions in their own possessions.
In spite of this in 1776 the United Provinces were the first country to salute the Flag of the United States, leading to growing British suspicions of the Dutch. These suspicions seemed to be confirmed in 1778 when the Dutch refused to take Britain's side in the war against France, even though the Republic was obliged by treaty (1678) to do so. Also, the Dutch claimed the British had no right searching their ships for weapons for the rebels, contending that "contraband" should be interpreted in the narrow sense of goods belonging to the enemy. The Republic then officially adopted a policy of armed neutrality. This would allow the French to use Dutch colonies — that is, in effect all the key locations in the trade to Asia — as supply stations.
Dutch naval power had been in decline since 1712. The Dutch navy, now having only twenty ships of the line, was no match for the British Royal Navy.
Britain had already gained supremacy of the high seas over France long before, in the Seven Years' War. The Dutch fought a skirmish with the British at the Battle of Dogger Bank, but after this tried to avoid any other major fighting.
The Dutch had hastily embarked on a major shipbuilding project of 84 warships between 1777 and 1789. Due to all kinds of misfortune (storms, collisions, strandings), about a third of the Dutch fleet sank or was captured between 1782 and 1784. Coordination with its war allies, France and Spain, was poor. The new ships were not ready in time to prevent Britain from taking effective control of the Dutch colonies (in India all of the Dutch colonies were taken) making William V a puppet, only able to rule with Prussian military assistance (Triple Alliance (1788)).