On 13th June in 1667, the Dutch took advantage of a demoralised, angry England to launch an unexpected attack on the Royal Navy in the Medway, successfully destroying or capturing 20 ships.
Diarist Samuel Pepys reflected the country's anguish with these famous words:
“Home, where all our hearts do now ake;
For the news is true that the Dutch have broke
The chaine and burned our shops, …
I do fear so much that the whole kingdome is undone”
The attack was the latest in an ongoing battle between England and the Netherlands for control of trade routes across the world.
When Charles II was restored to England's throne in 1660, national pride and optimism soared and the country grew more bullish in its plans to take Dutch trade.
Sensing this change in atmosphere, the Dutch began building bigger and heavier ships. The English, in contrast, had money problems that stopped them upgrading their fleet.
Relations between the two countries worsened when the king's brother, the Duke of York, captured the Dutch colony of New Amsterdam. The city was renamed New York in his honour.
The ongoing aggression drove the two sides to declare war in 1665, and the English got off to a good start with a resounding victory at the Battle of Lowestoft.
But England's buoyant mood was punctuated by two disastrous episodes, starting with the Great Plague in 1665 and followed by the Fire of London in 1666.
These devastating events hit England's finances hard and the people, who had lost loved ones, homes and jobs, took to the streets causing massive social upheaval.
Recognising England's low point, the Dutch launched an audacious attack.
The Dutch fleet of 30 ships was first spotted in the Thames Estuary on 6 June, but the alarm was not raised until 9 June, when the ships had made it to Sheerness.
The king sent his commander George Monck to Chatham to assess the situation. Monck found the boatyard unprepared for attack, with a lack of men, ammunition and defences in place.
He mounted hasty defences, including blocking ships to slow the enemy and a giant chain, stopping access to the dockyard.
But it was too late. The Dutch fleet arrived two days later and launched their devastating attack, breaking past the chain, sinking two of the guard ships and capturing their crews.
Seeing the hopelessness of the situation, Monck gave the order to sink 16 of the navy's ships so that they couldn't be captured.
The Dutch continued their progress into Chatham docks and sunk three more of the Royal Navy's biggest ships, before finally retreating with the prize of Royal Charles.
England was humiliated, its naval power destroyed and Charles II was concerned that the prestige of the crown would not recover.
The two sides made peace a few months later but the resentment continued, and they were back at war in 1672, this time with Charles II supporting a French-led conflict.
With the war going badly, the Dutch turned to William III of Orange to take control. He helped to turn the tide, building a reputation as the hero of Protestantism that would later see England's protestants invite him to take control of their throne.
Want to find out more? Join Professor Andrew Lambert, one of England's leading experts on the Royal Navy, to visit the dockyards of Chatham, Upnor Castle and the site of the Raid on the Medway, to learn more about Britain's fascinating naval history.
Picture credit: Attack on Chatham by Willem Schellinks c. 1668, credit: Thaliastock / Mary Evans