A transcript by John Thomas ('Sion Wyn o Eifion') of cywyddau and other poems by Robin Ddu, Rhys Goch Eryri, Iolo Goch, Tudur Aled, Dafydd Gorlech, Dafydd Llwyd ap Llywelyn ap Gruffudd, Dafydd ap Hwlcyn ap Madog, Rhys Llwyd ap Rhys, Maredudd ap Rhys, Mathew Owen, Edward Morus and Sion Lleyn; the manuscript also contains triads, genealogies, 'Breiniau Gwŷr Arfon', 'Meddygon Myddfai', 'geirlyfr William Lleyn', etc.