Windsor Castle is the largest inhabited castle in the world and the oldest in continuous occupation. Together with Buckingham Palace in London and Holyrood Palace in Edinburgh, it is one of the principal official residences of the British monarch. Windsor Castle is located in the Berkshire town of Windsor, in the Thames Valley to the west of London. Queen Elizabeth II spends many weekends of the year at Windsor Castle, using it for both state and private entertaining. Windsor Castle dates back to the time of William the Conqueror. Most of the kings and queens of England have had a direct influence on the construction and evolution of Windsor Castle, which has been their garrison, fortress, home, official palace, and sometimes prison. The castle's history and that of the British monarchy are inextricably linked. Chronologically the history of the castle can be traced through the reigns of the monarchs who have occupied it. When the country has been at peace Windsor Castle has been expanded by the additions of large and grand apartments; when the country has been at war the castle has been more heavily fortified. This pattern has continued to the present day. Queen Elizabeth II decided in 1952 to make Windsor her principal weekend retreat. The private apartments which had not been properly occupied since the era of Queen Mary were renovated and further modernised, and the Queen, Prince Philip and their two children took up residence. This arrangement has continued to the present day. On 20 November 1992 a fire which began in the Queen's private chapel quickly spread. The fire raged for 15 hours until it had destroyed nine of the principal staterooms, and severely damaged over 100 more - in all the larger part of the upper ward. One-fifth of the floor space of the Windsor Castle was damaged - an area of 9,000 square metres. The restoration program took five years to complete, 70% of it funded by the decision to open to the public for the first time the staterooms of Buckingham Palace. The total cost of repairing the damage was £37 million (the US $59.2 million). The restoration was undertaken at no additional cost to the British taxpayer. So successful was the Windsor Castle restoration due to the faithfulness to the original plans and decorations, the distinction between old Windsor Castle and new is hard to detect. Explore the most significant jewel of our heritage by Tourope UK's top blue badge guides today.