Twenty-five years ago, two days after the 9/11 attacks, Queen Elizabeth II broke centuries of royal protocol by ordering the Star-Spangled Banner to be played during the Changing of the Guard at Buckingham Palace, a symbolic gesture of solidarity with a grieving America. Custom had held that a foreign anthem should only be played during state visits, but thousands of onlookers, many wrapped in American flags and in tears, gathered to witness the tribute, which was followed by a two-minute silence.

The Coldstream Guards band, in traditional bearskin hats, performed the anthem during a 45-minute service before playing further American pieces including "Amazing Grace" and "Hymn to the Fallen". Three days later, at a memorial service at St Paul's Cathedral, the Queen again broke with tradition by singing along to the anthem and shedding a tear, later telling Americans that "grief is the price we pay for love". She went on to visit the World Trade Center site in 2010 and had the anthem played again at Windsor Castle for the 20th anniversary in 2021, with the tradition repeated once more this year to mark the 25th anniversary.