According to the plaque positioned at its base, this tree commemorate Queen Victoria's Golden Jubilee in 1887. Queen Victoria became the monarch when she was only 18 years old. She was a popular queen and went on to celebrate the 60th anniversary of her accession in 1897.
The plaque is postioned on the northern side of the tree and reads:
Jubilee Oak C.F.M.S. 1887
However, the oak boasts an impressive 6.8 m girth so the tree is much older than 120 and was probably a large tree even when Queen Victoria was born.
Grey's Court is owned by the National Trust. An entry fee is charged to enter the garden in order to help maintain this property and gardens. The oak can be viewed from a public footpath running between the National Trust car park and Broadplatt.