 The decision to build the redoubt was made at a conference held in Rochester on 21 October 1804, to discuss defence against Napoleon's planned invasion of the United Kingdom, preparations for which were gaining momentum on the opposite side of the English Channel.The meeting, which was attended by the Prime Minister, William Pitt the Younger, agreed to adopt a revolutionary scheme to build a chain of mutually-supporting circular artillery towers along a stretch of the Channel coast where the French were thought to be most likely to land.The scheme had been devised by Captain William Henry Ford of the Royal Engineers and championed by Brigadier-General William Twiss who commanded the Royal Engineer Southern District.