The Battle of Crécy is the first in a series of three books covering the major land battles of the Hundred Years War, that attempt to enforce the English claim to the throne of France by right of inheritance, and to regain those English possessions in France lost by King John in the 1200s. Edward III of England, through his mother, was the nearest male relative to the last Capetian king of France, and in the time of Henry II of England in the 12th century the king of France ruled less French territory than did the king of England.

The war was not, of course, a hundred years of fighting.  Rather it was a series of campaigns and battles lasting rather more than a hundred years but interspersed by truces and armistices, some lasting for many years.  That English armies were so successful during this period was due to a genuine revolution in military affairs, which rested on three legs.

The first leg was professionalism, where soldiers were paid a set rate, were subject to a form of military law and had a recognisable chain of command.  There had not been professional soldiers in the modern sense since the collapse of the Western Roman empire in the 4th and 5th centuries.

The second leg was the use of technology as a force multiplier, in this case the longbow.  The longbow was England’s weapon of mass destruction, consistently ignored by England’s enemies and thus consistently slaughtered by it.

The third leg was the realisation that disciplined infantry, properly trained and equipped and on ground of their own choosing could see off any number of mounted cavalry, how ever well bred that latter might be.  It quickly became obvious to thinking French soldiers – and there were some – that it was the longbow that was the battle winner, but they dare not emulate England by investing in archery themselves, for to arm the lower orders risked their turning against their masters.

English society was remarkably mobile at the time, when men who joined as private soldiers in the ranks of the archers could, with ability, rise to be knighted and placed in command of armies. French society, on the other hand, was stultified with the only route to nobility or the gentry being by birth. English society was one where men were comfortable with each other, regardless of rank.

This book traces the causes of the war and describes how the English military system imposed after the Norman Conquest gradually mutated into that which allowed stunning victories over far larger forces.  It was one thing to win the battles, however, and quite another to control the territory thus captured, and as the series goes on, covering Poitiers (1356) and Agincourt (1415) it will show why King Charles of England is not also King Charles of France.

Gordon Corrigan is the author of Sepoys in the Trenches, and Wellington: A Military Life. Crécy is his latest book.