Now it is in quite good order, something I can say with pride and satisfaction. But there is a lot of stone work that needs replacing and we also have to replace the six statues that used to be on the roof. We haven’t been able to do a lot of restoration over the past four years because all the monies have been drawn to rewiring, costing hundreds of thousands of pounds. If John Churchill were to return here today I think he would be delighted to see that the place is still in reasonably good nick. The other thing is that one has constantly got to think of other means of attracting outside events. It’s no use sitting back and thinking you can carry on the business in the same way that it was done 25 years ago. There’s a lot of outside competition now.

The one thing that has really hit the stately homes business quite badly is Sunday opening. There has been a huge change to the way of life in this country on Sundays. Fifteen to 20 years ago there was very little that people could do on Sundays except visit a stately home. The shops were shut, no race meetings took place. That’s all changed.

So we have to keep innovating. This year we have restored the Secret Garden, a treasure that has remained hidden for more than 30 years.

The garden was conceived by my father, the 10th Duke, and work began in 1960 on creating a romantic and secluded haven which broke away from the formal nature of traditional Victorian gardens.

My father was a keen gardener and planted unusual species of trees, shrubs and flowers to create a Four Seasons garden comprising winding paths, soothing water features, bridges, fountains, ponds and streams.

Over the past 30 years, the garden has grown wild and remained inaccessible to all but the most intrepid of explorers. However, a team of dedicated gardeners set about restoring it to its former glory.

We are constantly having to come up with things to make people aware that there is more to Blenheim than just the house.

At our music festival this year, for example, we had Barry Manilow performing on the final night. I’m a great Barry Manilow fan – he’s performed here before and I know him quite well.

You have to cater to all sections of the community, especially children, because they quite often tell the parents what they’ll be doing at weekends.

If anybody is interested in history or heritage then automatically they’ll want to come to Blenheim. Here, you will find not just the history of our family but to some extent an insight into the history of Britain since the 1700s.

Our special exhibition on the Battle of Blenheim explains just how important that victory was. If the French had won they would have dominated the world – the Americans might well have ended up speaking French.

Whenever I’ve been away from home, it is still a great thrill to return. I love seeing the house again as I come down the drive but I also have a nagging anxiety: “What new problem is there now to fix?”

It has to be that incredible room the Long Library – it’s 180ft long and was designed by Vanbrugh as a picture gallery. The room’s proportions are amazing.

From here you look out over the Water Terrace Gardens laid by my grandfather down towards the lake. It’s a very big room. It needs quite a lot of people in there, say 300, to make you realise just how big.

My Favourite Painting

I would choose that 1905 painting of my grandfather and grandmother by John Singer Sargent. The painting hangs in the Red Drawing Room and shows my father standing between his father Charles, the 9th Duke, and his mother Consuelo with the Blenheim spaniels. It’s quite magnificent – a wonderful composition.