In the Geoffrey presented Merlin as a south Welsh prophet who gives advice to the 5th-century kings
Vortigern,
Aurelius Ambrosius and
Uther Pendragon, but the Merlin of the
Vita seems to be a significantly different figure, still a prophet but also a warrior-king turned madman active in the 6th-century
Hen Ogledd (Old North). Geoffrey explicitly identified the two Merlins by making the hero of the
Vita a king of Dyfed in south Wales and by having him reminisce, as a preternaturally long-lived man, about his career in the previous century as recorded in the
Historia, but the poem nevertheless gives the impression that two different legends have been with some difficulty yoked together, a south Welsh one and a north British one. The Celticist A. O. H. Jarman proposed in the 1950s that the south Welsh legend concerned a prophet called
Myrddin, associated with the town of
Carmarthen (in Welsh Caerfyrddin) and named after it, while the northern legend was about a wild man called
Lailoken who took part in the
battle of Arfderydd in 573. These two stories, argued Jarman, became fused into one composite legend long before the was written, and Geoffrey simply used different parts of the story in the
Historia and the
Vita. This theory was accepted by most late-20th century scholars, but has been challenged by
Rachel Bromwich and
Oliver Padel, who have each proposed the possibility that Geoffrey himself was responsible for uniting the southern legend of Myrddin and the northern legend of the
wild man. Among the most important analogues of the are a small number of
Middle Welsh poems.
Cyfoesi Myrddin a Gwenddydd ei Chwaer ("The Conversations of Myrddin and his Sister Gwenddydd") consists mainly of questions by Gwenddydd and prophecies in response by Myrddin, who is represented as a madman. Rhydderch and the battle of Arfderydd are mentioned.
Yr Afallennau ("The Apple-trees") is a poem containing much prophecy and also a lament by the narrator over his own circumstances. He has spent fifty years wandering, a madman among madmen, in the Caledonian Forest, having survived the battle of Arfderydd. There are references to Gwenddolau, Rhydderch and Gwenddydd. In
Yr Oianau ("The Greetings") the narrator lives in the wilds with a little pig, both suffering from the persecution of Rhydderch. At one point he mourns the death of Gwenddolau. Finally,
Ymddiddan Myrddin a Thaliesin ("The Dialogue of Myrddin and Taliesin"), includes a prophetic description of the battle of Arfderydd, but does not otherwise contain much legendary material. The figure of Lailoken appears in three Latin sources: a
Life of St. Kentigern written by
Jocelin of Furness at some point between 1175 and 1199 but containing material that may derive from a lost 11th century
Life, and two short narratives, not easily dateable, called
Lailoken A and
Lailoken B. The
Life of St. Kentigern includes an episode in which a
homo fatuus (meaning either idiot or jester) called Laloecen at the court of Rhydderch correctly prophesies the king's death. In
Lailoken B the hero detects the queen's adultery by a leaf caught on her shawl, but is discredited when he predicts his own death in three different manners, only to be vindicated when he is beaten, transfixed by a stake, and drowned in the river Tweed.
Lailoken A has the
threefold death story without the adultery, and also presents him as a wild man of the woods whose misfortunes are a punishment for his having caused a battle easily identifiable as the battle of Arfderydd; he is also explicitly identified with Merlin (
Merlynum). An Irish analogue to the
Vita exists in the tale of
Buile Shuibhne. In this work, written in the 12th century but based on earlier stories, the warrior Suibne goes mad during the
battle of Moira and escapes into the wilderness. Though he is cured and re-enters society he relapses and returns to the wilds, and his wife remarries. Some details of the
Vita may be taken from other Celtic sources. One of Merlin's prophecies, it has been argued, includes a reminiscence of the 10th-century prophetic poem
Armes Prydein. The description of the first finding and capture of Merlin shows close resemblances to an episode in the
Vita Gurthierni, a life of
St Gurthiern of
Quimperlé. The name Morgen appears in the as the eldest of
nine sisters who tend King Arthur in Avalon. Though this is the first explicit appearance of Morgan le Fay in literature there have been many attempts to trace her origins in various earlier Celtic goddesses. The
Vita names Barinthus as the helmsman of the ship that took Arthur to Avalon, and he has been identified as the Barrintus who told
Saint Brendan of a wonderful island in the western ocean, but it is uncertain which version of the Brendan story Geoffrey came across. Geoffrey was not entirely dependent on Celtic sources for his poem. As a humanist writer of the
12th-century Renaissance he had a knowledge of much classical and medieval Latin literature at his command, and this fact is evident in his , even in his choice of meter, the classical
hexameter. Merlin and Taliesin's conversations together on cosmology, natural history and geography largely derive from medieval Latin writers associated with the
Chartres School and from
Isidore of Seville's
Etymologiae, a 7th-century encyclopedia which was hugely popular through the Middle Ages. The theme of Merlin's laughter at the beggar and at the man buying leather has analogues in Greek and Jewish literature that can be traced back to the
Talmud. Other writers who have been suggested as minor sources of the
Vita include
Solinus,
Rabanus Maurus,
Bede,
Pomponius Mela,
Ovid,
Virgil,
Horace,
Apuleius,
Boethius,
Bernardus Silvestris,
Adelard of Bath,
Lambert of Saint-Omer, and the author of the
De imagine mundi. == Criticism ==