The Shining Company (1990), young-adult fiction by Rosemary Sutcliff, is set in the Dark Ages and provides a lead-up to the Battle of Catraeth in 600 CE.
The Shining Company won the Phoenix Award in 2010.
Prosper, the second-born son of the chieftain Gerontius, was born in a small village in what is now called Great Britain. On his twelfth birthday, Prosper receives a servant named Conn from his father. Conn has an injured knee that Prosper must tend to, much to the young man’s disappointment. With help from his foster sister, Luned, Prosper tends to the injury and they become friends.
Later that summer, they meet Phanes of Syracuse, a merchant who is getting his dagger repaired. Phanes tells them tales of the dagger’s origin from Constantinople. This encounter makes Conn want to pursue metalsmithing, a craft bondsmen are forbidden to practice.
Prosper, Conn, and Luned see a white hart while searching for their lost dog. They make a promise to each other to tell no one about it. However, the news reaches the King's son Gorthyn, who arrives intending to hunt the hart. Prosper, Conn, and Luned plan to kill the hart humanely if the hart is cornered, but Prince Gorthyn calls off the hunt at the sight of it. This action makes Prosper give his allegiance to the Prince. When Prosper turns sixteen, Gorthyn appoints him his second shield-bearer at the host of Mynyddog the Golden, King of the Gododdin. Conn accompanies Prosper on the trip.
The group arrives at Dyn Eidin to meet with Mynyddog. They expect the host to be primarily a discussion of impending war against the Saxons of Bernicia, who are growing in power. However, Mynddog is visibly ill. Mynyddog’s friend Phanes of Syracuse talks to Prosper, explaining that the King is too ill to participate so his illegitimate son, Ceredig the Fosterling, will take his place in the host. The feast and sword giving take place, comprising three hundred sons of chieftains from kingdoms across the land (called the Company). Prosper meets Cynan Mac Clydno and his devoted friend the Princess Niamh.
The Company begins training with its shieldbearers. Conn has no place or role until Prosper sends him on an errand to the weaponsmith and, seeing his fascination with the craft, proposes to grant him an apprenticeship, which would force his father to free him.
Prosper and two other shieldbearers are assigned to spend three days doing anything except for sleeping. So they set out for the Roman fort of Castellum, where they gossip and practice stone-masonry. They discover another party completing the same assignment, which leaves a token in their camp as a challenge. On the third night, Prosper’s party returns, finding the other group asleep. They attack the group in jest, but Prosper ends up in a fight with a panicked Faelinn, the shieldbearer to Peredur of Rheged.
For one year, the Company goes through rigorous training to become a fighting force like old King Arthur's three hundred. Every night, they feast in the great hall at Dyn Eidin. Here, Conn is not known as a slave, so he is able to practice the craft of swordsmithing.
At the Midwinter feast, the Company and the King's bodyguard Teulu fight. In spring, envoys from the Dalriada arrive to be persuaded to join Mynyddog's cause; the envoy demands that two men from the Company catch a third running toward the cliff known as Epona's Leap. Prosper is chosen as a runner and Faelinn as his catcher. As Prosper has previously fought with Faelinn, he is scared of what Faelinn might do.
News of Aelle of Deira’s death spreads throughout the Company. Aethelfrith of Bernicia takes control of both kingdoms; Mynyddog sends out a summons of war to the kingdoms of the North and West. The Company rides to Catraeth with the intention of holding the ground until reinforcements arrive. While wandering outside the camp, Prosper and Cynan come upon a Saxon shepherd. They are forced to kill him to ensure his silence, which becomes Prosper's first experience of war.
The Company secures the Royal Village, but Aethelfrith of Bernicia escapes. In the next days, the Company raids and defends against the growing Saxon army while waiting for reinforcements. Prosper's Prince Gorthyn and fellow shieldbearer are killed, along with Cynan Mac Clydno's brothers and Faelinn's master Peredur. When the Company has dwindled to less than three hundred from the original nine hundred, the Fosterling sends down an ultimatum. Since they cannot escape or expect reinforcements, they must die and take as many enemy combatants as possible with them. They also have to cover the escape of a messenger, Aneirin, escorted by Conn and other field-smiths. Cynan takes Prosper and Faelinn as his shieldbearers and the Company readies to say goodbye.
As the Company rides out, they begin to drop and die almost immediately. Prosper and Cynan find themselves alone when Cynan is hit by an iron-studded club. Prosper drags him off to rejoin Conn's party. While he recovers from his injury, the group heads back to Gododdin land, but Cynan is listless and silent. When they reach Gododdin land, Aneirin and Prosper tell the King's Hall the story of the Company, and Mynyddog explains that since the other kingdoms did not answer his summons, he could not throw away the rest of the Gododdin war host reinforcing the Company. Cynan collapses, and at the end of four days of fever, tells Prosper that the King betrayed them. Prosper and Niamh spend the summer caring for Cynan. When he recovers, Cynan declines to resume his place in the Company, offering to return Phanes's dagger to its owner. Prosper advises Conn to return to Nant Ffrancon as a free man and marry Luned; he leaves with Cynan, not to return to Mynyddog’s company.