Knole House in Sevenoaks, Kent, is to receive £7.75m for repairs and conservation from the Heritage Lottery Fund.
The funding will also go towards the construction of new visitor facilities at the 15th century medieval palace, a former hunting lodge to Henry VIII.
The National Trust said that since acquiring Knole in 1946, it had faced expensive running battles with rain, damp, mould and insects, but the funding meant the future of the mansion and its treasures were now secure.
More top news
The unlicensed events unfolded on Saturday night at Clapham Common and Tooting Bec Common.
A 37 year old man who was taken to hospital after getting into difficulty in a stretch of water near Maidenhead has died.
Jonty Bravery, who is mentally ill, has been jailed for 15 years after throwing a six year old boy from the Tate modern balcony.