Windsor Castle is the largest inhabited fortification of its type anywhere in the world and it still serves as the principal official residence of Queen Elizabeth II. Built upon a high natural elevation, the castle was begun by King William I to guard the western approaches to London. The earliest remaining stonework was raised by Henry II between 1173 & 1179 and virtually every monarch since have left their mark. In 1348, King Edward III established the Order of the Garter here, an elite group of English knights based upon King Arthur’s legendary court. The ceremony is still carried out in St George’s Chapel on April 23^rd. In all, 10 kings, 7 queens and many princes and princesses are interred in the stone vaults of the chapel.