Notebooks and loose papers containing drafts and notes by Taliesin Williams relating to various books and essays, especially to his unpublished works on Merthyr Tydfil (T5/1-5), Llandaff (T5/6-13) and Sion Cent (T5/14-16).
Also included are papers relating to Coelben y Beirdd, Cyfrinach Beirdd Ynys Prydain and possibly other publications (T5/17-18, see also T5/4) and fragments relating to his essay on the Neath Valley (T5/19).