Buckingham Palace, is the symbol of reigning monarch of the United Kingdom. In 1837, Buckingham Palace became the principal royal residence. Every year some 50,000 invited guests are entertained at garden parties, receptions, audiences and banquets. The Garden Parties, usually three, are held in the summer, usually in July. The Forecourt of Buckingham Palace is used for Changing of the Guard, a major ceremony and tourist attraction. PM Modi will also visit the palace for official lunch with Queen Elizabeth.