An imperfect manuscript, compiled during the 1540s, containing holograph Welsh translations or adaptations by Elis (Ellys) Gruffydd, 'The soldier of Calais' (fl. c. 1499-1552) of astrological and medical texts (see 'Llawysgrif Cwrtmawr 1' by Delwyn Tibbott in National Library of Wales Journal, Vol. XI, No. 3 (1960), 276-83). The principal contents are ['Prologue Tholomews']; 'Compost Tholomews'; 'y llyshieuwr', largely from Laurence Andrewe: The vertuose boke of Distyllacyon of the waters of all maner of Herbes ... (1527); 'Kastell yr iechyd', from Thomas Elyot : The Castel of Helth (1539) (see S. Minwel Tibbot (gol.) : Castell yr Iechyd, (Caerdydd, 1970)); and 'y llyuyr oaviechyd y hrai baach ai meneginaethavl' from Thomas Phaer : The Regiment of Lyfe (1544).