The Battle of Crécy, fought in northern France with a large contingent of Cornish soldiers, was largely funded by sales of Cornish tin.  The battle took place between a French army commanded by King Philip VI and an English army led by King Edward III.  The English army had almost reached Paris, sacking many towns on the way, before marching north, intending to link up with an allied Flemish army when they encountered the French.  The result was the routing of the French and the besiegement of Calais by the English which, after its surrender, remained in English hands for almost two centuries.

One of the most important English commanders was Sir John Treffry of Fowey, which at the time was one of the most important ports in Southern England.