In response to public outcry that the palace was not flying a flag at half mast , Queen Elizabeth II ordered a break with protocol , replacing the Royal Standard with the Union Flag at half-mast as soon as the Queen left the Palace to attend the Princess 's funeral at Westminster Abbey . The Royal Standard was again flown ( at full hoist ) on her return to the Palace . Since then , the Union Flag flies from the Palace when the Queen is not in residence , and has flown at half mast upon the deaths of members of the Royal Family , such as Princess Margaret and the Queen Mother in 2002 and other times of national mourning such as following the terrorist bombings in London on 7 July 2005
terrorist bombings in London on 7 July 2005
7 July 2005 London bombings
Half-mast