These stunning pictures show a towering tree standing as tall as a country house nearly 100 years after it was planted - by Queen Mary.
The massive cedar was put in the ground as a sapling by Queen Elizabeth II's grandmother in 1922.
The Forestry Commission has released released a black-and-white photo taken at the time of the Royal planting.
It shows Mary, who ruled as Queen consort from 1911-1936, dressed all white with a grand hat as she stands beside a woman holding the chest-high blue Atlas cedar tree.
Today, 97 years later, the magnificent tree still stands, and has grown as tall as the historic country house it stands beside Westonbirt School in Westonbirt, Glos.
Queen Mary, wife of Queen Victoria's grandson King George V, was invited to Westonbirt House to plant the cedar by the wealthy Holford family, who were great friends of the Royals.
The Holfords, formerly Masters of Chancery in London, created Westonbirt Arboretum, the National Arboretum in Gloucestershire, a mile away from the site of Queen Mary's cedar.
It is believed that the Queen consort was a regular visitor to Westonbirt Arboretum.
During the heyday of Victorian plant gathering, the Holfords financed trips to the far corners of the British Empire.
They would always bring back rare, beautiful and exotic plants to grow in the Arboretum.
Today, the botanical collection is home to more than 2,500 tree species.
Andy Bryce, Collection Manager at Westonbirt Arboretum, said: "The Forestry Commission is steeped in fascinating history, from its inauguration after the First World War, through to the present day.
"Like our arborist and collection teams do now, Queen Mary planted the blue atlas cedar for the benefit of future generations. We're delighted that it still stands today."
September 1 marks 100 year since the passing of the Forestry Act, and the creation of the Forestry Commission.
Today, Forestry England looks after more than 1,500 forests and woodlands and welcomes over 230 million visits each year.
The Forestry Commission is marking its centenary this year by inspiring people to connect with trees and woodlands, and to help protect them for the future.
A programme of activities has included the Big Forest Find, the largest ever survey of forest wildlife, and works by sculptor Rachel Whiteread and poet Carol Ann Duffy.
The Commission's centenary year has also seen new areas of woodland creation, and projects focused on the health benefits of visiting the forest.