Most of the letters, 1897-1917, relate to the author's academic and antiquarian researches into Pembrokeshire history. Many are enquiries to be answered by J. H. Davies. There are also occasional references to local affairs and family matters.

The letters, 1900-1925, concern books, publishing, printing and librarianship matters. Many of the letters relate to the publication of J. H. Davies's Bibliography of Welsh Ballads. Some concern the affairs of the Welsh Bibliographical Society or the Carmarthen Antiquarian Society, and some derive from D. Rhys Phillips's work as Welsh Librarian at Swansea.

Manuscripts, estate records and papers of the Wynne family of Bodewryd, Anglesey, including records of the Bodowyr estate (Bodedern), Anglesey, and Plas Einion estate, Denbighshire, and papers of the Owen family of Penrhos, Anglesey; important Welsh literary manuscripts, legal manuscripts relating to civil and ecclesiastical law; the antiquarian collections of Edward Wynne, chancellor of Hereford, relating to Wales and to the diocese of Hereford, and part of the collection of Humphrey Humphreys, bishop of Bangor and later of Hereford; letters to Humphrey Humphreys, 1691-1709 (mainly 1705-1709); Wynne family correspondence, 1613-1816; legal papers, [17 cent.]-[18 cent.], especially relating to a lengthy action between Chancellor Edward Wynne and the Mostyn estate following the purchase by Wynne of the Bodowyr estate, 1721-1746; estate, personal and household accounts, 1603-1753; and title deeds, [13 cent.]-1864.

The letters, 1904-1924, concern Francis Green's antiquarian researches and publications. Many concern the Historical Society of West Wales of which Francis Green was secretary. The file also contains a stray letter, July 1911, from Walter Spurrell to Francis Green.