The first rendition of God Save the King was sung at St Paul’s Cathedral to mark the end of the memorial service for the Queen on Friday night.
The lyrics to the national anthem have changed from "Queen" to "King" and "her victorious" to "him victorious" to mark that King Charles III has now taken over as the new monarch.
It comes after crowds spontaneously sang the version of the song outside of Buckingham Palace on Friday as the King arrived with the Queen Consort.
The anthem is also expected to be sung at the Kia Oval on Saturday as the England v South Africa Third Test Match resumes. The match was paused on Friday following the Queen's death.
Members of the Royal Family did not attend the 6pm service at St Paul's, which was open to the public and was broadcast live by the BBC.
However, an audio of the King's televised address to the nation was played inside the cathedral.
A total of 2,000 seats were allocated to the public on a first-come-first-served basis, with all of the wristbands for the evening service being distributed within three hours, a cathedral spokeswoman said.
Ahead of the service, a hundreds-strong queue formed, winding from St Paul's to beyond the Tube station streets away.
Attendees were dressed smartly in black suits and ties while others wore black mourning veils as they waited to take their seat inside the cathedral.
New Prime Minister Liz Truss also attended the service, and gave a Bible reading from Romans 14.7-12.
Dame Sarah Mullally, Bishop of London, as Dean of the Chapels Royal, delivered the address, while Archbishop of Canterbury Justin Welby gave the blessing.
