Sir Robert Herries (1730-1815) was the eldest son of William Herries of Halldykes, Dumfriesshire, and his wife Katherine né Henderson. Herries moved to the Netherlands as a young man, where he joined the Amsterdam bankers, Hope & Co. With their assistance he established himself as a wine merchant in Spain, at the age of just 23. In 1762 he joined the famous banking firm of Coutts, later developing his own highly successful international banking and tobacco trading business. He was knighted in 1774 and served as MP for Dumfries Burghs, 1780-84. He married first his cousin Grace (d. 1773), daughter of John Henderson of Broadholme, and secondly, on 12 August 1777, Catherine, daughter of Rev. Francis Hender Foote of Charlton House, Bishopsbourne, Kent, and his wife Catherine, third daughter of Robert Mann of Linton. She was born c.1754 [in HAM/1/17/148 Herries notes that she was about the same age as the Duchess of Atholl who was born in 1754]. She was the widow of John Ross.
The correspondence in this sub-series largely comprises letters from Lady Catherine Herries to Mary Hamilton, although there are also letters from her husband Sir Robert, and from Sir Robert's daughter by his first wife, Nina Herries. Lady Catherine and Hamilton were clearly close, and her letters are amongst the most revealing in the archive. She discusses a wide range of topics, including social engagements and invitations to Hamilton and her husband; her own health (especially her deteriorating eyesight) and the health of her family and friends; Hamilton's dispute with a Mrs Cole (HAM/1/17/63); Hamilton's engagement and marriage to John Dickenson and her subsequent pregnancy (e.g. HAM/1/17/80); the birth and childhood of her daughter Louisa; the Herrieses' excursions to France, visits to spas such as Bath (HAM/1/17/2, /66, /147-148, /210-212, etc.) and Buxton (HAM/1/17/154-161), and to Brighton (Brighthelmston) for sea-bathing (HAM/1/17/80, /221-222); and the Royal family and Court gossip.
Catherine Herries also discusses numerous leading literary and artistic figures with whom she associated, such as Elizabeth Carter (e.g. HAM/1/17/71, /81, /85, /93, /101), Mary Delany (HAM/1/17/2, /49, /55, /63, /72, /106), Elizabeth Montagu (HAM/1/17/71, /87, /257), Hannah More (HAM/1/17/58, /91, /237), Hester Thrale Piozzi (HAM/1/17/72, /73, /93), Joshua Reynolds (HAM/1/17/3), Horace Walpole (HAM/1/17/55, /115), and the 'milkwoman' poet Ann Yearsley (HAM/1/17/35, /36, /37, /58). She also discusses her reading matter and practices, including Francis Bacon (HAM/1/17/56), James Boswell (HAM/1/17/57), and Samuel Johnson (HAM/1/17/58).
It appears that the correspondence may have been a little one-sided, especially in later years, for Catherine Herries regularly laments the long silences from Hamilton (e.g. HAM/1/17/171, /177, /197, /203, /204, /206, /222, /232, /237, /238, /248).