King Charles and Queen Camilla, Burnham and his wife Marie-France van Heel, and Macron and wife Brigitte are being shown key scenes in the tapestry, including the Coronation of King Harold and his death in battle.
School children from the UK and France are attending the event, with the King and the French president expected to make speeches marking the historic loan.
Sending the tapestry to the British Museum had been announced by Macron during the French state visit to the UK in July 2025, as an emblem of the strong partnership between the countries.
There had been some worries that moving the fragile tapestry could risk causing damage, but French government sources said ahead of the royal preview: “The display conditions at the British Museum are ideal.”
The French authorities welcomed the way that visitors in London would see the tapestry lying flat, rather than upright, with this believed to be better for the conservation of the fibres, sewn more than 900 years ago.
It is believed the final scenes of the tapestry have been lost or destroyed, as it has not always had such careful owners. In the 18th Century, during the French Revolution, it was rescued from being cut up to make covers for soldiers’ carts.
At a state banquet hosted by King Charles in Windsor, Macron had said the missing end of the tapestry was a symbol that “in the great mural of Franco-British history, the end is yet to be written – it is up to us to do it”.