The group comprises mainly letters written to members of the families related by marriage to Griffith of Garn, such as Hughes of Gwydir, Llwyn Gronw, Cae'r berllan and Weeg, 1713-1823, Roberts of Bryn y neuadd, 1705-1757, and Wynne of Garthmeilio and Plasnewydd, 1793-1831, together with miscellaneous recipients, 1680-1882, mainly on Caernarfonshire and Denbighshire parliamentary elections, church matters, inheritance, debt and domestic affairs.