Books like The Iron Grail

After long travels, Merlin has returned to Alba, the future England. Likewise, Urtha, High King of the Cornovidi, is coming home as well. And Jason is sailing in on the Argo, to seek his son who hides somewhere in the kingdom.But Urtha's stronghold has been taken by warriors from Ghostland. They claim it as their own. Now there will be war--against the Otherworld.In this sequel to Celtika, myth and history weave together into a tale of honor, death, and magic. At the core of the story is Merlin himself, the enchanter in the prime of his life, reckless, curious, powerful, yet a stranger to his own past--a past that is catching up with him.