1782: The American Plot to Kidnap the Future King of England

Prince William Henry was the son of George III, the King of Great Britain and Ireland and the man whom the United States Declaration of Independence called a tyrant who was "unfit to be the ruler of a free people."
At the time that the Continental Congress proclaimed those words, Prince William Henry was 10 years old. When he was 13, he became a midshipman in the Royal Navy. Accounts at the time note that he was good at that demanding job.
In September 1781, General George Washington was marching most of his army away from New York City, which had been under British occupation since 1776, to a great victory the following month at Yorktown, Virginia. At the same time, Prince William Henry's ship sailed into the harbor of New York City on HMS Prince George, the flagship of Admiral Robert Digby.
This was the cause of great excitement, as it was the first time that a member of the British royal family had ever visited America. Prince William could have become the center of the New York social scene, but instead he kept quietly on his ship or in his quarters in Hanover Square in lower Manhattan, which he shared with Commodore Edmund Affleck.
Colonel Matthias Ogden, an American spy, watched and listened carefully for a few months. He learned that the prince was lightly guarded. This was a great opportunity. If the Americans could capture Prince William, they could improve their position at peace talks. So he pitched the idea to General Washington. Washington wrote back with his approval on March 28, 1782:

Sir,
The spirit of enterprise so conspicuous in your plan for surprising in their quarters, & bringing off the Prince-William Henry & Admiral Digby, merits applause; and you have my authority to make the attempt in any manner, & at such a time as your own judgment shall direct.
I am fully perswaded, that it is unnecessary to caution you against offering insult or indignity to the persons of the Prince, or Admiral should you be so fortunate as to capture them; but it may not be amiss to press the propriety of a proper line of conduct upon the party you command.
In case of success, you will, as soon as you get them to a place of safety, treat them with all possible respect, but you are to delay no time in conveying them to Congress, & reporting your proceedings with a copy of these orders.
Given at Morristown this 28th day of March 1782.
Go: Washington
Note Take care not to touch upon the ground w[hi]ch is agreed to be Neutral – viz from Raway to Newark & four miles back.

Colonel Ogden drew up a detailed plan, including the numbers and skills of the men needed, the equipment they would carry, the precise order of their actions, and the ideal weather conditions desired. This was an amphibious raid deep inside enemy territory, so everything would have to work perfectly.
Unfortunately for Ogden, General Sir Henry Clinton, the British commander in New York City, learned of the plot--or something like it. He immediately increased the number of guards around Prince William, Admiral Digby, and himself. As a result, Ogden never got the chance to attempt his scheme.
Shortly thereafter, the prince sailed away with his shipmates. He ascended to the British throne in 1830 with the name of King William IV. He reigned for 7 years before dying at the age of 71.