The 1939 deposit consists of deeds and documents, 1549-1887, relating to properties in Montgomeryshire, Merionethshire, Breconshire and Shropshire. The 1973 deposit mainly contains deeds and documents, 1564-1932, relating to properties in Montgomeryshire, many relating to the Lloyd family of Montgomery. The 1979 deposit comprises materials gathered by J. D. K. Lloyd for a History of Montgomery; a bundle of deeds and documents, [19 cent.]-[20 cent.], relating to the family of Lloyd of Plas Trefaldwyn, Montgomery, and Castell Forwyn, Abermule; photographic albums, 1898-1978, comprising mainly family photographs; a collection of over 1000 postcards and photographs of historic buildings throughout Europe; and seven manuscript maps of land in Montgomeryshire, 1772-1858.

Topographical, historical, and genealogical material relating mainly to the counties of Anglesey, Caernarvon, Denbigh, Merioneth, Montgomery, and Shropshire, accumulated by Thomas Pennant and including letters or other contributions from Paul Panton, Hugh Davies (botanist), E. R. Owen (Bangor), John Thomas (Llandegai and Beaumaris), John Lloyd (Caerwys), Sir John Cullum (Hardwick), Richard Thomas (Llanegryn), Thomas Bownall (London), Thomas Jones (Caernarvon), George Ashby (Cambridge), John Price (Oxford), Thomas Ford Hill (London), Foote Gower (Chelmsford), Francis Leighton (Shrewsbury), J. Plymley (junior), J. Worthington (Llanrhaiadr ym Mochnant), Thomas Addenbrooke (Buildwas), David Pennant, and Richard Gough (Enfield).