Bertrand du Guesclin is one of the great French heroes of the Hundred Years War. His career may have developed more slowly than that of the meteoric Joan of Arc whose fame and myth have overtaken his own, but it lasted much longer, and his story is every bit as remarkable.

The son of an obscure and minor Breton noble, he rose in the 1360s and 1370s to become the Constable of France – a supreme military position: it outranked even the princes of the blood royal, and had always been the exclusive preserve of the princes themselves or the greatest magnates. He was unlettered, he was knighted late, he was defeated, captured and ransomed more than once; but through campaigns ranging from Brittany to Castile he achieved not only fame as a pre-eminent leader of Charles V's armies, but a dukedom in Spain, burial among the kings of France in the royal basilica at Saint-Denis, and recognition as nothing less than the ‘Tenth Worthy’, being ranked alongside the nine paragons of chivalry who included Alexander the Great, Julius Caesar, Charlemagne and King Arthur.

His is a truly spectacular story. And the image of Bertrand, and many of the key events in his extraordinary life, are best known and have been essentially derived from The Song of Bertrand du Guesclin, this epic poem by the otherwise unknown Cuvelier. Commissioned (presumably, but we don't know by whom) and written immediately after Bertrand's death in 1380, it was extremely successful: seven manuscripts have survived of Cuvelier's original version composed in verse, which has been translated here; even more survive of the prose redaction produced in 1387, some five years or so after the verse; and ‘the Cuvelier tradition … has been the principal source of all subsequent biographies of the Constable’.

But the poem itself has been largely ignored or disparaged.