The millionaire boss of Reading Football Club has donated £3m to London's Royal Academy of Arts.
John Madejski is a long-term supporter of the Academy
The windfall has restored the Academy's Burlington House fine rooms, which have been unavailable for public viewing for more than two centuries.
The new space means rare works of art by artists such as Turner, Constable and Hockney will come out of storage.
The rooms have been renamed the John Madejski Fine Rooms in recognition of the donation.
The restoration has taken four years and a total of £6 million has been raised to make the renovation possible.
A Royal Academy spokeswoman said: "The Fine Rooms have mostly been used in the past internally for meetings, internal functions and evening events.
"In one room, ceiling paintings and gilding had been painted over and we have taken the rooms back to how they were meant to be."
A long-time supporter of the Piccadilly gallery, Mr Madejski has also loaned the Academy a ballerina sculpture by Edgar Degas for the next two years.
Petite danseuse de quatorze ans (small dancer aged 14), a bronze sculpture of a young ballet dancer, is one of the artist's most significant works, according to the Academy.
Mr Madejski, owner and chairman of First Division Reading, said: "It is my pleasure to be able to share this stunning sculpture with everybody who visits the Royal Academy."
The Fine Rooms, which are being officially opened by The Prince of Wales on Friday, will be open free to visitors from 13 March.