Taliesin (c. 534 – c. 599) is the earliest poet of the Welsh language whose work has survive. His name is associated with the Book of Taliesin, a book of poems that was written down in the Middle Ages (John Gwenogvryn Evans dated it to around 1275, but Daniel Huws now dates it to the first quarter of the 14th century). Most of the poems are quite late in date (around 10th to 12th century), but a few are earlier, and eleven of them, according to Ifor Williams, date from the 6th century. The historical Taliesin is believed to have been a bard who sang in the courts of at least three Celtic British kings of that era. In legend and medieval Welsh poetry, he is often referred to as Taliesin Ben Beirdd ("Taliesin, Chief of Bards"). A few of the "marks" presumably awarded for poems - or at least measuring their "value" - are extant in the margin of the Book of Taliesin. The mythological Taliesin's life is found in several late renditions (see below), the earliest being in the hand of Elis Gruffydd (mid-16th century), who may have relied on existing oral tradition about him. His name was spelled as Taliessin in Alfred, Lord Tennyson's Idylls of the King and in some subsequent works.