Syon House, the Duke of Northumberland’s family residence, is to be opened up to corporate functions. The Duke has granted permission for the ‘secret garden’ of the Grade One listed mansion in Isleworth, west London, to be used for public functions for the first time this summer.

From 20 June to 9 July, a luxury marquee will be erected in the grounds of the former rose garden. The marquee will hold up to 600 people for a formal event or up to 1,000 for less formal gatherings.

Event organisers and caterers Tapenade will manage all events that take place in the marquee, handling everything from food and drinks to entertainment and furnishings. Paul Vesper, Tapenade director, said: "We are holding a range of functions at Syon House this summer. Our executive chef John Hearn and his team will create a variety of high-quality cuisine to complement each individual event and theme."

Guests will enjoy champagne and canapés in the Long Gallery before being shown through a secret door where elegant stone steps leading to the beautiful ‘secret garden’ just 100 metres from the house.

"We are looking forward to organising the very first events in the secret garden at Syon House," said Vesper. "These will certainly be unique and memorable occasions."