The collection consists largely of correspondence between Dawson, Tisdall, Bury and Marlay family members and from a wide array of prominent contempories, from the eighteenth to the early twentieth centuries. Particularly significant is the role of Lady Charleville, and correspondence between her and other women in the family circle make the collection particularly rich for domestic and social history. The family's literary and intellectual tastes are also evident. Subjects range from management of family estates to contemporary events, social, political and cultural. Occasional correspondents include Shelley, writing as a schoolboy at Eton, Maria Edgeworth and Amelia Opie.
Within the series concerning Charles Brinsley Marlay survive a number of bundles concerning the Belvedre Estate in West Meath. References can be found throughout the papers to the Charleville's own seat at Tullamore, King's County.
A number of journals covering various European tours are present, together with sketch books and commonplace books. In Charles Marlay's papers can be found printed ephemera, including theatre programmes, posters and newspaper cuttings from the late eighteenth century.
The earliest manuscript present is a copy of William Bercher's 1559 work, 'A Dyssputacion of the Nobylytye off Wymen'. Papers with it record the editorial process which led to its publication by the Roxburghe Club in 1905.