Keywords: Ernwlf (Brut y Tywysogion).jpg Arnulf de Montgomery's name Ernwlf as it appears in a particular passage in the Welsh Brut y Tywysogion Peniarth MS 20 page 96 The passage concerns Arnulf seizing the castle of Pembroke The National Library of Wales website The manuscript dates to the 14th century It is unknown who compiled the manuscript PD-Art PD-old-100 14th-century manuscripts |