The founder of the family was Gilbert Elliot (1651-1718), a younger son of Gavin Elliot of Midlem Mill. Gilbert Elliot was admitted to the Faculty of Advocates in 1688, created a baronet in 1700, and appointed a Lord of Session as Lord Minto in 1705; he acquired the lands of Headshaw in Roxburghshire in 1696, and added Minto to his property in 1703. Sir Gilbert Elliot, 2nd Baronet (1693-1766), likewise had a distinguished legal career, becoming a Lord of Session as Lord Minto in 1726, a Lord of Justiciary in 1733, and Lord Justice Clerk in 1763. Sir Gilbert Elliot, 3rd Baronet (1722-1777), was both a leading figure in the Scottish Enlightenment and an active politician at Westminster. Sir Gilbert Elliot, 4th Baronet (1751-1814), whose political and diplomatic career culminated in his appointment in 1807 as Governor-General of India, was created Baron Minto in 1807 and Earl of Minto in 1813; he assumed the additional surnames of Murray Kynynmound in 1778 on succeeding to his mother's properties, and his successors likewise assumed these additional names on succeeding to the earldom. His eldest surviving son, Gilbert, 2nd Earl of Minto (1782-1859), served as a Cabinet Minister in the Whig Ministries of Grey, Melbourne and Russell. William Hugh, 3rd Earl of Minto (1814-91) was an active member of both the House of Commons and the House of Lords. The public career of Gilbert John, 4th Earl of Minto (1845-1914), culminated in his appointments in 1898 as Governor-General of Canada and in 1905 as Viceroy of India.

The Minto Papers richly document the activities of the leading members of the family, and are a valuable source for the study of most aspects of Scottish affairs in the eighteenth and nineteenth centuries, including the local history of Roxburghshire; of British politics in general, circa 1740-1914; of war and diplomacy in Europe and east of the Cape in the eighteenth and nineteenth centuries; of Italian affairs in the early and mid nineteenth century; of Canadian affairs in the late nineteenth century; and of Indian affairs in the early nineteenth and the early twentieth centuries. But the collection also contains the papers of equally distinguished younger sons, as well as of related families, which extend even further the range of subject matter.

The papers of the diplomatist, Hugh Elliot (1752-1830), are a rich source for the general political history of Europe in the years circa 1770 to 1806.

The papers of the Honourable Sir Henry George Elliot (1817-1907) are chiefly concerned with European diplomacy and the Eastern Question in the years 1868 to 1884.

The papers of Admiral John Elliot (1732-1808) contain material concerning lead and copper mining in the eighteenth century.

The Elliot of Wells papers are chiefly concerned with the Commissariat to the allied army in Germany, 1761-1764, and with the Government of Ireland in 1806-1807, as well as containing estate papers concerning lands and families in Roxburghshire, Surrey, Cornwall and Northamptonshire.

The National Library's holdings of the Minto Papers are not complete.

Letters of David Hume to Sir Gilbert Elliot, 3rd Baronet, (published in J Y T Greig (editor), ‘The Letters of David Hume’ (Oxford, 1932) are no longer with the collection.