An elderly Christian monk who secretly records his youthful past as a fierce pagan warrior. Born a Saxon but captured in a raid as an infant, he miraculously survives a sacrificial pit and grows up on Merlin's estate at Ynys Wydryn. He dreams of joining the battle lines rather than entering the Druid priesthood, eventually rising to become a dedicated soldier in the British armies.

The illegitimate son of High King Uther and a highly capable, charismatic warlord. Banished by his father after a tragic battle, he returns from exile to serve as the protector of the infant king Mordred. He combines physical intimidation in plated armor with an unexpectedly gentle, jovial demeanor off the battlefield.

One of the last remaining Druid priests in a land increasingly converting to Christianity. He is a wealthy, eccentric landowner who gathers orphans and outcasts at his sanctuary to train a new generation in the old ways. His long absences create anxiety among his followers, leaving his household vulnerable to political attacks.

A striking, highly intelligent noblewoman with strong facial features and red hair. She harbors deep ambitions for power and rejects the meekness of the growing Christian faith, preferring the mystery and authority of the goddess Isis. She quickly moves to cultivate a royal court surrounded entirely by beautiful things and loyal followers.

The High King of Britain, an aging and bitter monarch whose physical health is rapidly deteriorating. He clings stubbornly to old pagan traditions while trying to manage a kingdom fracturing under the constant threat of Saxon invasions. He harbors a deep, unforgiving resentment toward his illegitimate son, Arthur.

An Irish survivor of a slaving raid who serves as Merlin's most dedicated and fierce acolyte. She feels the presence of the gods within her, using a mix of genuine magic, illusion, and sheer psychological terror to defend her domain. She forms an intense, permanent blood-bond with young Derfel.

The ambitious, treacherous King of Siluria. He happily employs both pagan Druids and Christian priests to secure whatever political or military advantage he needs in the moment. He views the crippled infant king as a weakness to be exploited rather than a sovereign to be protected.

The powerful, prideful King of Powys, a wealthy northern British kingdom. He commands immense military resources and fiercely protects his royal dignity. He views Arthur's sudden political maneuvers and broken betrothals as unforgivable insults to his family line.

A young queen in the frame narrative who visits the monastery where the elderly Derfel resides. She acts as Derfel's patron, secretly supplying him with parchment so he can record his true history of Britain. She prefers romanticized tales of magic and pristine knights, often expressing disappointment at Derfel's gritty historical accounts.

A fiercely devout Christian clergyman who views paganism as a blight that summons Saxon invaders. In his youth, he is an ambitious priest looking to build his influence through wealthy converts. In the frame narrative, he is the strict, unsympathetic bishop overseeing Derfel's monastery.

The infant grandson of High King Uther and the sole legitimate heir to the throne of Dumnomia. Born with a clubbed foot, he represents the fragile, vulnerable future of the British kingdoms. Various factions immediately begin vying for control over his upbringing and the power that comes with it.

The Christian princess of Dumnomia and the widow of Uther's slain heir. She is fiercely determined to raise her newborn son in the Christian faith, viewing the religion as a shield against the barbarism of the Saxons. Her religious fervor and desperation for stability often blind her to obvious political treachery.

The illegitimate daughter of King Uther and a dedicated pagan priestess. Her body carries severe burn scars from a fire that killed her husband. The scarring fuels her foul temper and intimidating presence, and in Merlin's absence, she serves as the de facto leader of the pagan sanctuary.

A dark, cruel Druid in the service of King Gundleus. He is a harsh practitioner of the old faith who years ago condemned the infant Derfel to be thrown into a sacrificial death pit. He becomes deeply unsettled upon realizing that the boy survived his curse.

King Uther's chief warrior and a highly seasoned, formidable commander in the Dumnomian army. He is a pragmatic and sometimes ruthless soldier who values the spoils of war and personal enrichment above strictly honorable conduct. He acts as an early mentor figure for Derfel on the battlefield.

A Saxon captive who serves as a slave and personal assistant to Morgan. She quietly helps care for the infant Mordred when the royal party temporarily relocates to Merlin's stronghold.

A young girl raised in Merlin's community who becomes Derfel's early companion when he joins Arthur's fighting forces. She transitions from the rugged life of a military camp follower to joining the more refined, comfortable court established by Guinevere.

The extraordinarily beautiful and charming princess of Powys. She approaches arranged political betrothals with grace and optimism, representing the potential for a lasting peace between warring British kingdoms before impulsive decisions tear the alliance apart.

The crown prince of Powys and the designated heir to King Gorfyddyd. Unlike his more belligerent father, he proves open-minded and eager for a lasting peace with Dumnomia, possessing diplomatic foresight in a violent age.

The eccentric scholar-king of Armorica, an allied kingdom across the sea. He prefers collecting Roman manuscripts and maintaining a beautiful, culturally rich citadel over adequately funding his military defenses against encroaching Frankish invaders.

The handsome, preening prince of Armorica. He is highly concerned with his public image and actively employs bards to sing of his glorious achievements in battle, though he rarely faces genuine physical danger himself. He maintains a serpent-like aloofness that masks his deep insecurities.

The younger prince of Armorica, who stands as the complete opposite of his boastful brother. He is a genuinely valiant, noble fighter who is acutely sensitive to his own flaws, possessing a melancholic outlook on the fading glory of the British world.

A woman technically held as Arthur's slave, but who practically serves as his lover and the mother of his twin sons. She deeply understands Arthur's consuming ambitions and the political realities he ignores, remaining a grounded, albeit marginalized, presence in his life.

The young king of Kernow, a minor kingdom that relies heavily on Dumnomia's military protection. He bravely demands a blood price when his people are slaughtered, insisting on justice despite lacking the military strength to threaten his larger neighbors.

A fearsome, pragmatic Saxon king who leads massive incursions into British territory. He travels with vicious war dogs and a massive retinue, operating strictly on the brutal logic of land, wealth, and conquest rather than honor or diplomatic treaties.

A minor king who straddles the line between old traditions and new comforts, wearing facial tattoos while living in a Roman-style villa. He instigates internal violence by feeding Owain rumors of hidden wealth in a neighboring settlement.

The aging king of Gwent, a kingdom caught in the crossfire between Dumnomia and Powys. He commands low-morale troops and struggles to decide whether to honor his military alliances or surrender to overwhelming force.

The son of King Tewdric of Gwent. He openly questions the value of fighting Arthur's battles when his own kingdom faces immediate annihilation.