As the Royal Family assemble at Sandringham this week, all eyes will be on the Christmas Day walk to church for a rare joint outing for the Cambridges and Sussexes.

And anyone who is wondering what will happen behind closed doors may be in luck, as the Royal Collection Trust embraces the public’s festive fascination to publish the first official book sharing the real story of a Royal Family Christmas.

From the monarchy’s first Christmas tree to the gilded peacocks once served for lunch and photographs of the Queen herself performing in pantomime, the book is designed to give an insight into the traditions that have survived all the way to 2018.

It discloses how the current Royal Family will spend their Christmas Eve and Day, from their embracing their German ancestry in swapping gifts, to the last minute additions to the tree.

Tracking festive celebrations through the ages, it will tell how the family’s first Christmas trees were brought by Queen Charlotte from her native Germany,and how the roast turkey was popularised by Edward VII.