Eventually the family regained possession, but two thirds of the enormous house was gradually demolished. What remained was used during WWII as a training school for Polish resistance fighters. When English Heritage gained possession, it was practically derelict.
The story of the restoration of the nurseries was interesting. They found two water-colours of the rooms painted by the young ladies of the family in Victorian times. Also, in another part of the house, the original dolls' house was discovered.
Using the paintings as a guide, English Heritage had carpets and wallpaper designed and manufactured. They moved the dolls' house back to the nursery, and collected toys and furniture of the period.
The governess's room. After going through a number of governesses, the family had the same one for many years. She eventually became companion to one of the painting daughters, who never married.
As a result of the demolition of a large part of the original house, it ended up with only one staircase, that is without back stairs for the servants. The family was liable to meet maids and footmen carrying hot water and coals up to the bedrooms and nurseries. They invented a novel solution: an upstairs coal "cellar." A winch was run from a window to the ground and coal was hauled up (300 tons a year, if I remember correctly) and stored here:
Here's a close-up of a bucket used to carry hot water to the rooms. It must have been pretty heavy when full.
As I mentioned, Charles II, the Merry Monarch, owned Audley End for a few years, when it was still enormous. He must have spent quite a bit of time there, enough to make it worthwhile also buying a house in a nearby village for his mistress, Nell Gwynn. We had a bit of a hunt for it but found it at last:
Nell Gwynn's house