Buckingham Palace and changing of the gaurds

Throughout the three days I was in london Buckingham Palace was the hub location and meeting place for my brother and I.  The palace is the official residence of Her Royal Majesty Queen Elizabeth II.  With beautiful classical designed, it first became the official residence of the Monarchy in 1837 upon Queen Victoria's accession to the throne. To determine if the queen is present you need look no further than the flag; if the gold and purple flag with HM's coat of arms is flying, then the queen is there, otherwise the union jack will be flying in which case she is probably meeting with dignitaries across the world or else spending time at one of her many other residences.