'Sir Gawain and the Green Knight' is one of the landmarks of medieval English literature and we know of it because a small manuscript survived from the 14th century.
Now catalogued in the British Library as 'Cotton Nero A x', the manuscript includes three other poems, thought to by the same poet.
One is a masterpiece.
This is 'Pearl' and in this documentary Julian May brings it out from the dark shadow of Gawain's tale of beheading and questing into the light where its lustre can glow.
Pearl is the poet's two year old daughter, who has died.
Her grieving father falls asleep on her grave and Pearl appears to him in a dream and leads him to some understanding of this calamity.
Yet while he takes some comfort from this he not reconciled to her loss, and needs to grieve.
In this feature Jane Draycott, who has just published a new translation; Bernard O'Donoghue, the poet who teaches Medieval Literature at Oxford University; the American poet and critic Dana Gioia (who himself lost a child in infancy) all reveal the way this ancient poem of great beauty as well as sadness speaks to us today.
Though a reflection on a death, it is full of life; though a dream poem, it is vivid and real; though an expression of orthodox Christianity, it is a poem of human relationship and feeling - and not without wit and humour when Pearl, as daughters do, lectures her father, and he, as fathers do, complains she's getting a bit uppity.
The poem is of great formal elegance and intricacy, itself a linguistic string of pearls and there readings of it by James Layley, from Draycott's translation and Trevor Eaton in the original Middle English.
And at the British Library, Julian Harrison, the curator who looks after the manuscript, shows Julian May this diminutive book, no larger than a paperback, for someone's personal reading and well-thumbed, that contains two of the treasures of the English language.
Producer: Julian May.
How a poem of love, loss and solace speaks from the 14th century to us today.