The Restoration of the Stuart monarchy in Britain in 1660 did not mean an end to all of the policies of Oliver Cromwell and the Commonwealth, especially with regard to trade. At that time the United Provinces of the Netherlands dominated world trade, a position that the English regarded with jealous eyes. Trade disputes – mainly caused by restrictions on foreign trade to English ports brought about by the Navigation Act of 1651 – and the English use of privateers to search Dutch merchantmen brought the two countries into open conflict during Cromwell’s reign.
The First Anglo-Dutch War lasted from March 1652 to May 1654. Fought entirely at sea it resulted in an English victory. As part of the Treaty of Westminster, the Dutch reluctantly recognised the Navigation Act; however, the underlying issues that brought the countries to war had not been resolved. The Dutch response to a series of diplomatic incidents and English attacks on Dutch colonies and shipping provided the pretext for the English to declare war on 4th March 1665.
As with the first war, the fighting was limited to naval engagements; mostly confined to the North Sea. The initial English successes did not provide the decisive victory required to force another capitulation from the Dutch. Indeed, the strength of the reconstructed Dutch navy and their financial might meant that as the war dragged on into 1667, the British king, Charles II, struggled to find the money to maintain his navy. As a result of this, he decided to moor his largest ships at Chatham Docks, on the River Medway, while he negotiated with the Dutch and conducted secret talks with the French for extra funds. Meanwhile, the Dutch made plans to end the war with a decisive blow: an amphibious assault on Chatham Docks.
The plan was hatched by the Dutch statesman, Johan de Witt, whose brother Cornelis accompanied the force with the sealed orders for the attack – secrecy being of the utmost importance. Late in the day on 9th June 1667, the English sighted thirty ships entering the Thames Estuary. The attacking fleet carried around one-thousand marines, who captured strategic positions at Canvey Island and Sheerness on either side of the mouth of the river. Over the next few days the Dutch fought their way up the Thames and then the Medway removing the ships sunk by the English to impede their progress. On 12th June, the Dutch engaged the Royal Navy ships defending the chain at Gillingham, which protected the docks. Once they captured the HMS Unity and destroyed the Matthias and Charles V with a fireships, the docks were at their mercy.
In response, the Royal Navy sank the ships further up the river to prevent their capture – in total they sank thirty of their own ships during the raid. The Dutch seamen continued to fight their way into the docks until their withdrawal on the 14th June. The mission was a complete success, the Dutch destroyed fifteen ships and sailed away with two more, including the pride of the English fleet: HMS Royal Charles. With his Navy in tatters, King Charles II was left with little choice but to sue for peace. A month later his representatives signed the Treaty of Breda, which granted the Dutch possession of some of the territories they captured during the war, concessions regarding the Navigation Act, and also freed up their forces just as the French invaded the Spanish Netherlands to their south.
You can read a contemporary account of the raid in the Diary of Samuel Pepys available at Project Gutenberg.