"Y Gododdin" is known only from a 13th-century manuscript, so it is impossible to determine whether this passage is original or a later interpolation, but John Koch's view that the passage dates from a 7th-century or earlier version is regarded as unproven; 9th- or 10th-century dates are often proposed for it.Several poems attributed to Taliesin, a poet said to have lived in the 6th century, also refer to Arthur, although these all probably date from between the 8th and 12th centuries.