The outstanding items in the collection are the two diaries written by William Bulkeley (1691-1761) of Brynddu, Llanfechell, and covering the years 1734-1743 and 1747-1760 respectively. Another volume of diaries, extending from 1743 to 1747 was obviously at one time in existence, but was lost or misplaced before the collection reached the Library. Other items from this collection are six manuscript volumes associated with Mrs Elizabeth Morgan, wife of Henry Morgan of Henblas, and consisting of household accounts, 1732-1775; inventories of pewter and linen, etc., 1734; and of store-rooms, 1734; a record of gardening operations, 1754-1772; and cookery and medical recipes. The collection also includes the original manuscript of Henry Rowlands's Mona Antiqua Restaurata (1723) and a book of recipes and medicines from the early eighteenth century belonging to Rowlands's sister, Amy Rowlands; a book of pedigrees of Gwynedd families formerly belonging to Humphrey Humphreys, Bishop of Bangor (1689-1701); a seventeenth-century manuscript volume containing, for the most part, arguments in Latin bearing on the questions set for the Oxford Acts, etc.; and a group of four manuscripts written by Chancellor Edward Wynn of Bodewryd consisting mainly of notes and sermons.
It was necessary to adopt the Henblas A designation to distinguish these manuscripts from the bulk of the estate papers that were deposited in the Library in 1944, namely Henblas B.