A twelfth-century poem newly translated into English casts fresh light on the origin of today's Francophobic stereotypes.

Although it is meant to be an 'entente cordiale', the relationship between the English and the French has been anything but neighbourly.

When the two nations have not been clashing on the battlefield or the sporting pitch they have been trading insults from 'frogs' to 'rosbifs'.

Written between 1180 and 1194, a century after the Norman Conquest united England and Normandy against a common enemy in France, the 396-line poem was part of a propaganda war between London and Paris.

Poet Andrew de Coutances, an Anglo-Norman cleric, describes the French as godless, arrogant and lazy dogs. Even more stingingly, he accuses French people of being cowardly, and calls them heretics and rapists.

It has taken David Crouch, a professor of medieval history at Hull University, months to complete the translation of what is one of the earliest examples of anti-French diatribe.