Queen Elizabeth II health live updates: In critical condition

Queen Elizabeth II, who is Britain's longest serving monarch, is under medical supervision.

All of Queen's children including Prince Charles, Princess Anne and Prince Edward are now at her side.

Prince William, the Duke of Cambridge, landed in Aberdeen and will travel to Balmoral.

The Duke of Sussex Prince Harry, who was earlier reported to be travelling with his wife and Duchess of Sussex Meghan, will now travel to Balmore alone.

Political and religious leaders in the UK have expressed their concerns over the Queen's health.