The name Merlin

Glennie calls Merlin, with Taliessin, Llywarch Hen, and Aneurin, one of the four great bards of the Arthurian Age. I have no reason to doubt this is any other Merlin than the necromancer. It was also in Glennie's book that I found the tantalizing reference to Merlin's twin sister, Ganieda.

Spence believes that Merlin's story became fused with that of Ambrosius Aurelianus, accounting for the mages' alternate names "Merlin Emrys" and "Merlin Ambrosius". Merlin was probably more a title or office than a personal name.

Chrétien de Troyes alludes to Merlin exactly once, and then in a context suggesting that the mage may already have been legendary by Arthur's time: in Erec and Enide appears the observation that in Arthur's day sterlings had been the currency throughout Britain since Merlin's time.