An archive of historic documents has been saved for the nation after it was bought by the University of Southampton for £2.8m.
The vast Broadlands Archive contains the papers of the Victorian prime minister Lord Palmerston, among others.
The university acquired the archive with the help of a £2m grant from the National Heritage Memorial Fund (NHMF).
Funds from the sale will be spent on repairs to the Grade I listed house at Broadlands, Romsey, Hampshire.
Among the documents is a handwritten note from Mahatma Gandhi to the last viceroy of India, Lord Mountbatten, where he writes about his vow of silence.
Professor Chris Woolgar, head of special collections at the university, said the archive was hugely important. "Without them we would find it difficult to understand fully the foundations of the independent states of India, Pakistan and Bangladesh," he said.
The archives also contain 1,200 letters from Queen Victoria to Lord Palmerston who between 1830 and 1865 was foreign secretary, home secretary, then prime minister.
Also included are the diaries of Anthony Ashley Cooper, 7th Earl of Shaftesbury, who was a social reformer.
A NHMF spokesman said the diaries offered a "remarkable insight" into the mind of the man known as the "poor man's earl".
He said: "Lord Shaftesbury tirelessly championed the cause of the poor working class, most famously, the protection of child chimney sweeps and shorter working hours for children in factories."
The archives come from the Broadlands estate, which was home to the Temple family, who held the Viscount Palmerston title, as well as the Ashley, Cassel and Mountbatten families.
The Broadlands Archive has been on loan to the university's Hartley Library since 1989 and is stored in purpose-built facilities.