Shortly after Kelly O’Driscoll started her new job as the head of built heritage at Blenheim Palace, the parlous condition of the enormous, Sir John Vanbrugh-designed pile made itself known. A stone cannonball detached from a frieze high up on the building in Woodstock, Oxfordshire, and landed on the steps below. 

“Luckily it was during the night,” she says, adding that it happened during the Christmas period when there were thousands of visitors. “It was quite intimidating.”

Now the frieze and other stonework adorning the building are being restored as part of a £12m project to replace an acre of roof over the part of the building centred on the main entrance. The work also includes the repair and restoration of the Great Hall painted ceiling by Sir James Thornhill and Louis Laguerre’s paintings of the Battle of Blenheim in the adjacent saloon which have been damaged by leaks through the roof. 

“When it snowed, we would have buckets in the Great Hall with water dripping through the painting,” O’Driscoll says.