Set around 600AD -- long enough after the departure of the Romans for their presence to be a folk-memory, yet with Roman ruins still inhabited and Artos the Bear (Sutcliff's portrayal of the historical King Arthur, in The Lantern Bearers) still a hero -- The Shining Company recounts the tale of three hundred warriors who make a last valiant stand against the Saxons.
The story is a retelling of 'The Gododdin', the first surviving North British poem, written (or at least created) by the bard Aneirin. Sutcliff tells the tale from the point of view of Prosper, the second son of a minor chieftain, whose quiet life alters course on the day that Prince Gorthyn arrives to hunt a magical white hart that roams the Welsh hills.
A couple of years later, when he's grown to manhood, Prosper, along with his bondsman (and friend) Conn, answers Gorthyn's summons to train as a warrior (not one of the three hundred, but a shield-bearer and backup) in King Mynyddog's army. Conn, meanwhile, finds himself drawn to the smithy: as a bondsman he can't train to be a smith, because smiths are free men and such training would grant him his freedom: but Prosper counts friendship more important than slavery, and Conn learns his trade with Prosper's blessing.
What I love about this novel is what I've always loved about Sutcliff's writing -- the detail, the sense of real people living, feeling, acting in famiiar ways, in a recognisable setting and a distinctly remote time. There are familiar moments: the sour taste of beer to one accustomed to wine, the smell of green wood burning, the thickening of the evening light. And there's the wider world in which these characters move: Prosper studying Latin and being aware of the Greek classics, in particular the tale of the three hundred Spartans; his fascination with the 'archangel dagger' that he's shown by a trader, who tells him that it was the cherished possession of an Emperor's bodyguard, and speaks to him of Byzantium. And because the framing narrative -- present in only the lightest of allusions -- is of an old man looking back on his life, that wider world has more significance to the reader than to the young Prosper.
The Shining Company is far from the best of Sutcliff's novels: I think it may have been her last. But it brings the period to life, and peoples it with characters more real and credibly flawed than most.