In the fifth century, long before Britain was united, in a brutal land of warring factions and tribes where lives were often fleeting, Arthur Pendragon evolves from outcast to legendary warrior and leader.
Episode 1
High King Uther banishes his son, Arthur, who rescues a dying boy named Derfel; Arthur entrusts Derfel to Merlin and Nimue; Uther has a new heir, but Merlin receives a dark vision for the future.
Episode 2
An untimely death leads Merlin to locate Arthur and urge him to come back to Britain; chaos ensues when Gundleus assaults Avalon.
Episode 3
Arthur takes Gundleus prisoner, and Nimue begins to plan her revenge; Arthur learns that Gundleus' uncle Gorfydd is preparing for war.
Episode 4
Bastard son Arthur returns to the land he's been banished from to find a kingdom in chaos. Seeking the aid of his oldest confidants, Arthur aims to right Britain's path as he faces the most unexpected of obstacles.
Episode 5
Nimue aborts her pregnancy and is later found by Merlin, who subsequently helps her; Derfel is uneasy about the attack on the mine that Owain is concealing; when Tristan shows up, he demands retaliation, but Owain claims he is innocent.
Episode 6
Arthur and the tribe kings enter peace talks; Arthur meets Guinevere, Ceinwyn's lady-in-waiting, while traveling.
Episode 7
Arthur and Guinevere meet secretly before Arthur and Ceinwyn are to be married.
Episode 8
Arthur believes Bedwin will be able to negotiate peace with Gorfydd. However, when Morgan and Derfel arrive in Powys, they discover Bedwin being crucified. A Christian mob accuses Nimue of poisoning them. They demand justice from Arthur.
Episode 9
Derfel and Morgan take Bedwin's body back to Arthur. Ceinwyn reveals that Gorfydd is allying with the Saxons. Derfel discovers that the Christians died of natural causes, but Arthur reveals he has exiled Nimue to the Isle of the Dead.
Episode 10
Derfel makes his assault on the Isle of the Dead and finds Nimue. Arthur meets the Saxon King Aelle and hands over information which will benefit their advance into Britain. In return, the Saxons will not attack Dumnonia for an agreed period of time.
