The Queen's funeral on Monday is expected to be one of the largest gatherings of royalty and politicians to be held in the UK for decades.
Invitations were sent out over the weekend, and some 500 heads of state and foreign dignitaries were expected.
The majority of leaders were asked to arrive on commercial flights and told they would be flown en masse from a site in west London.
The ceremony at Westminster Abbey has a capacity of approximately 2,200 people.
Here's what we know so far about who will and won't be in attendance.