It's used by many other countries as well!
The newly-crowned King Charles III got emotional during the queen's funeral at Westminster Abbey on Monday, as the service rendered the new version of the British national anthem, "God save the King."
The singing of the new national anthem followed a national two-minute silence at the end of an emotional service for Queen Elizabeth II. She died at the age of 96 on September 8, ending the longest reign by a single monarch in British history.
Although the teary-eyed king stood silent, his wife Camila, the queen consort, was by his side singing along to the lyrics of the new anthem.
“My mother’s reign was unequalled in its duration, its dedication and its devotion,” said the king in his address.
“Even as we grieve, we give thanks for this most faithful life. I am deeply aware of this great inheritance and of the duties and heavy responsibilities of sovereignty which have now passed to me.”
It wasn't the first time the national anthem has been played with the word king instead of queen since her death.
A recent service, held at St Paul's Cathedral in memory of the queen, marked the debut of the anthem's new version, as per the Independent.
A number of other royals, such as Prince William and Kate Middleton's young children, Prince George and Princess Charlotte, were also in attendance to mark the occasion.
"God Save the King" is the de facto national anthem of the United Kingdom and is even used by several of the UK's territories, including New Zealand, as an additional local anthem.
Earlier on Monday, the queen's coffin was set in motion, at the end of her four days of lying in State at Westminster Hall.
The king and other senior royals followed the procession on foot as the queen’s coffin arrived at Westminster Abbey, which will be her final resting place.
Hearse Winds Its Way Through London To Carry The Queen To Final Resting Place.youtube.com