I did take one great liberty with the historical facts of the assault. There was no disused western gateway, nor any mine either, but the idea for the mine came from an enormous and spectacular explosion which occurred in the city two days before the assault. It is believed that a British shell somehow ignited one of the Tippoo’s magazines, which then blew up. I changed the nature of that explosion, and delayed it by two days, because fictional heroes must be given suitable employment.