In order to facilitate rapid loading during battle, 18th Century musket cartridges were made from rolled brownish-white paper. This paper tube held both the powder and the ball was its own self contained wadding.
For training, reviews and firing a “feu de joie” or celebratory musket salute, however, blank rounds were needed. Numerous accidents were reported where a live round got mixed up with the blank cartridges. In 1790, the ordnance department had a solution: make the cartridges out of different colors of paper. Blank musket rounds would be made of the indigo blue paper, and live rounds would remain the brown or whited-brown color.
The new cartridge marking system worked well until May 15, 1800. On that day in Hyde Park (London) King George III was reviewing the grenadier battalion of the Foot Guards going through their field exercises with volley firing. During the dramatic display a musket ball flew past his Majesty and struck a spectator behind the King. King George immediately rode to the fallen man wounded in the thigh: “With his accustomed affability and condescension, His Majesty testified his sympathy at the occurrence, and instantly directed that the wounded gentleman should be taken care of by one of the surgeons of the regiment.” The King then returned to the demonstration and after the cartridges were inspected to insure all were blank, the firing was allowed to continue.
Immediately a military inquiry was ordered into the shooting by the king’s son, the Duke of York, who commanded the British Army. The concern was that Jacobite’s or republicans were in the Guards and had attempted to kill the monarch. What was discovered could be said the vanity of the Foot Guards was the culprit. Always wanting to have a little more flare than the rest of the army, the Guards had always made ALL cartridges from blue paper so that they matched the blue facings of their uniforms. Upon further investigation a cache of blue rounds with ball were discovered in the unit’s stores and were removed.
Though unfazed by the incident, the King now could rest a little more comfortably in his saddle at the next military field day.