With a massive girth of 7.60m this mighty tree is still able to dwarf the Hertfordshire Groundwork team. The oak was recorded as measuring 5.80m in 1830 by Strutt in Sylva Britannica.

It is the largest maiden, or clear-stemmed oak, in the country and is believed to have been planted by Queen Elizabeth I. Fittingly for a royal tree, it has a number of famous royal children and grandchildren; the Prince Consort Oak, planted by Prince Albert in 1861 near Speech House in the Forest of Dean, was grown from an acorn from this tree, and in 1957 Queen Elizabeth II planted an oak in the Forest of Dean grown from an acorn of the Prince's oak. The spade she used is now displayed on the wall of the Speech House.

Panshanger Great Oak - photograph courtesy of Chris Reynolds

It also drew the admiration of Sir Winston Churchill who, on one of his visits to Panshanger, planted an oak sapling grown from an acorn from this tree. Churchill's tree can still be found in the grounds.

Over the centuries, its size and form have frequently earned it attention. In 1789, it was described by the natural historian Gilbert White as "the finest and most stately oak in the south-east of England" and was the focus of a drawing by the artist Thomas Medland in 1841.