BNPS At least 60 Middle Age oaks have been unearthed in the grounds of Blenheim Palace

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At least 60 Middle Age oaks have been unearthed in a survey of the grounds of Blenheim Palace in Oxfordshire, with four of them measuring almost 30 feet in diameter. The huge width dates them to the Medieval period - between 960 and 1196AD. It was previously thought that Moccas Park, in Suffolk, Windsor Great Park, in Berkshire and Savernake Forest, Wiltshire, had the largest collection of the ancient trees, but the new research means Blenheim Palace has overtaken them. The 18th Century estate and UNESCO World Heritage Site is famous as the ancestral home of Winston Churchill - but its significance to natural history was previously unknown.

The 120 acre swathe of wilderness known as High Park was originally created by King Henry I for hunting, and was left untouched by gardening great Capability Brown when he started work there in 1764. It has been studied for the first time by Aljos Farjon, a leading botanist who is researching ancient oaks across the country for a book ‘Ancient Oaks in the English Landscape’, which will be published by Kew Publishing in 2017.

There is no other site in England that has so many ancient oaks in one site Aljos Farjon, Royal Botanical Gardens

He has looked at roughly 100 sites across England - which has the highest number of ancient oaks in Europe - and found that it has an incredible density of ancient trees packed into a small area. Medieval trees are aged by their width and measure between six and nine meter in diameter. Mr Farjon, Honourary Research Associate at the Royal Botanical Gardens in Kew, said: “There is no other site in England that has so many ancient oaks in one site, it is truly remarkable. “There is also no other place in the country which has so many nine metre trees, there are four alive and one standing dead.

BNPS Four trees measured almost 30 feet in diameter

“High Park has as many as 60 ancient oaks, which is not surpassed by any other site I know, but more interestingly these trees could go back further than the middle ages as they were not planted and simply grew. “The fact this landscape is important has been known for some time, but as High Park was not open to the public there has been no real investigation and I am the first person to study it. “I think when the estate was gifted to John Churchill, 1st Duke of Marlborough, in the 18th Century they just forgot about it or they didn’t have the money to change it, I’m not really sure, as it was not landscaped. “It was just not realised how important it was for its ancient oaks and the biodiversity that you get in these sites. “High Park offers a real glimpse into the past and is especially important in terms of fauna and flora - there are some species that will only survive in ancient oak land.

BNPS Satellite map with the ancient trees all marked - showing the extent of the forest

“There is not really anything like this in Europe. There are 22 sites of great importance in England and Blenheim Palace is right at the top of this. “High Park is in my view the most stunning site in Europe for ancient oaks.” The ancient woodland supports more than 100 different protected and notable species of fauna and fauna. Roy Cox, head of rural enterprises at Blenheim Palace, said: “It has been a protected site for over 50 years, but High Park’s significance has not been known until the last three or four years. “It is a hugely significant site, but in reality those trees are only seen by one person a year as it is such a sensitive area.

BNPS 1752 picture showing the ancient forest on a hill to the right of Blenheim Palace