Melville papers: Culture Secretary Fiona Hyslop announces the purchase at General Register House.
A major collection of historic documents regarded as one of Scotland’s "crown jewels" has been bought for £1.35m by the National Records of Scotland.
The papers of Henry Dundas and his son Robert, known as the Melville papers, contain around 11,000 records spanning 150 years in Scottish history.
The first Viscount Melville, Henry Dundas was Scotland`s foremost political figure in the late 18th and early 19th centuries, and is commemorated by the Melville Monument, a 150ft high column in Edinburgh’s St Andrew Square.
His dominance of the East India Company opened the lucrative British Empire to ambitious young Scotsmen and massively expanded Scotland's connection with India.
But he also promoted harsh punishment for rebellious colonists in the Americas and prolonged the abolition of slavery.
The purchase of his papers has been described as "a major coup" for Scotland.
The papers had been on long-term loan to National Records of Scotland (NRS) since 1951, until the Melville family decided to offer them for sale.
The purchase was funded by £725,000 from the Scottish Government and £625,000 from the National Heritage Memorial Fund. The £1.35m overall cost includes a discount agreed with the Melville family.
George MacKenzie, keeper of the Records of Scotland, said the purchase has saved the papers from being broken up and sold across the world.
He said: "We are enormously grateful that the Melville family offered us the first chance to acquire the collection when they decided to sell it.
"The Melville papers have been extensively used by the public since they were first loaned to us, and now that they're in public ownership we'll be working hard to make them even more widely available."
Colin McLean, of the National Heritage Memorial Fund, said: "Charting the American Revolution and War of Independence and the nation's struggle against Napoleon, the trustees of National Heritage Memorial Fund felt this archive was of such historical importance it must be safeguarded for future generations."
Daniel Szechi, Professor of early modern history at the University of Manchester, said: "Henry Dundas was the Grand Manager, and to his enemies the Great Tyrant, of Scotland for nearly 30 years.
"Henry Dundas also dominated the East India Company and used his power to open that most lucrative theatre of empire to ambitious young Scotsmen, massively expanding Scotland's connection with India and locking the nation's fortunes into Britain's global empire.
"The NRS is to be heartily commended for acquiring this superb historical collection."
Richard Finlay, Professor of Scottish history at the University of Strathclyde, said: "This is a major coup for the NRS.
"These papers are not only of great historical significance for our understanding of Scottish history, but will also be invaluable to scholars researching imperial and diplomatic history."
He added: "The Dundas dynasty was Scotland's greatest and most powerful political family since the Stuart monarchy."
Culture Secretary Fiona Hyslop added: "There are very few important politicians and military and naval men of the time who did not have dealings with the Dundases.
"Their influence over the government, politics and society of Scotland was extensive, and their legacy lives on in Scottish public life today in our street names, our statues and, now, in this public collection."
