The Queen and other members of the Royal Family will attend the annual Royal Festival of Remembrance.
This year the event at the Royal Albert Hall will mark the centenaries of the Battle of the Somme and the Battle of Jutland, the 25th anniversary of the Gulf War and the and the 80th anniversary of the first flight of the Supermarine Spitfire.
Other royals attending the service on Saturday include the Duke of Edinburgh, the Prince of Wales and the Duchess of Cornwall and the Duke and Duchess of Cambridge.
They will be received by Jon Moynihan, president of the Royal Albert Hall, and Vice-Admiral Peter Wilkinson, president of the Royal British Legion.
To mark Armistice Day on Friday, Prince Harry laid a wreath at the National Memorial Arboretum.
He attended a remembrance service at the Armed Forces Memorial alongside veterans and representatives of the Army, Royal Navy and RAF.
The prince was joined by hundreds of old soldiers and the loved ones left behind to mourn the dead, observing the silence in the chill autumn sunshine, in a mirror of services held across the country.