I picked up this book after reading an outstanding essay about essays by Paul Graham. His site has an F.A.Q., but most interestingly he also includes an R.A.Q. page for rarely asked but especially notable questions. While he writes mostly about tech and startups, Graham is a believer in the value of broad historical knowledge, and his recommendation of C.W.C. Oman’s The Art of War in the Middle Ages was enough for me to check out this little tome.

It’s a fine book: a cursory but entertaining overview of the important battles, tactics, and technologies from the period between the fall of the western Roman empire and the age of colonization. Like the rest of life during this period, war was especially brutal, but Oman’s appreciable wit had me smiling from time to time. He makes clear “the primitive state of the military art” at this time, when opposing generals would challenge each other to a battle at a specific time and place because without such an agreement,

there was apparently a danger lest the armies should lose sight of each other, and stray away in different directions. When maps were non-existent, and geographical knowledge both scanty and inaccurate, this was no inconceivable event. (62)

Oman doesn’t mince words about the French tendency to smugly value their nobility over military prudence. The armies of the French Kings Philip and John of Valois were

composed of a fiery and undisciplined aristocracy which imagined itself to be the most efficient military force in the world, but which was in reality little removed from an armed mob. (125)

And while (contrary to the joke) the French enjoyed plenty of victories, their folly in this respect is one of the great lessons of history. For chivalry’s sake, they fielded their proud knights long after pikemen and longbowmen proved more than their match.

The Rise of Knights

Rome’s well-armed, battle-hardened legions kicked ass for hundreds of years, but by the fourth century they had stretched themselves pretty thin. So under Constantine (emperor from 306 – 337), Rome “abandoned the offensive in war…having resolved to confine itself to the protection of its own provinces” (3). Cavalry can travel fastest, so a smaller number can respond to barbarian incursions more quickly than legions of infantry. Also, the tendency to keep cavalry together in one band improved morale, especially when compared with the legions, whose losses were increasingly replenished with questionably loyal men of conquered tribes. In additional to these logistical reasons, there was a tactical reason for Rome’s transition from infantry to cavalry as the backbone of its army. Their “barbarian” opponents were fielding more cavalry, whose powerful charges and ease of escape are an effective counter to guys on foot with swords. Thus the ascendancy of the mounted soldier.

Despite the fall of the Western Roman empire in the fifth century, the eastern Roman empire (known to their friends as the Byzantines) made supremely effective use of heavy cavalry¹, paving the way for the emergence of those most famous of heavily-armored cavalry, knights. For centuries, knights were a versatile and effective (not to mention charming) force, but two developments in weapons technology brought about their decline.

The Swiss Pikeman

There’s a famous line from my favorite noir film, The Third Man, which Orson Welles is said to have ad-libbed:

in Italy, for thirty years under the Borgias, they had warfare, terror, murder and bloodshed, but they produced Michelangelo, Leonardo da Vinci and the Renaissance. In Switzerland, they had brotherly love, they had five hundred years of democracy and peace–and what did that produce? The cuckoo clock.

There’s a lot wrong with Welles’ history there, not least that while the Borgias were doing their thing in Italy in the 15th century, the Swiss had the most formidable fighting force in Europe. Their brilliant idea: a 20-foot long pointy stick called a pike. These pikes were so long that when in formation the pikes of four rows of soldiers could stick out in front to strike at the enemy, like a shield of stabbiness the density of which prevented enemies from getting close enough to hurt them. And against cavalry the pikemen could plant the butts of their pikes in the ground and skewer knight and horse alike. Their only counter came much later on from artillery: cannonballs were brutally effective at tearing through such a tight formation.

The English Longbowman

Meanwhile, England had their own take on trying to kill the enemy before he gets close. Archery has of course been around since the stone age, but for two reasons archers played only a supporting role in medieval times. For one, knights began to wear plate armor which arrows had a hard time piercing. And also, archers’ range wasn’t so long that mounted knights couldn’t quickly close in and cut them to pieces. The longbow, with its greater power and range compared to a traditional bow, addressed both these shortcomings. This was proven dramatically at Crécy (in 1346) during the Hundred Years’ War, in a battle that signaled the end of the age of chivalry. Against the English King Edward III’s 11,000 men, Philip VI of France marshaled many times that number. But Philip’s men were slaughtered en masse. In their cavalry’s charge against the English, they were slowed by soft ground, which multiplied the effectiveness of Edward’s longbowmen. Cavalry’s prime defense is mobility: stripped of that, horses are just big targets. Many fell, leaving their riders to trudge through the mud beneath relentless volleys of arrows. Those that made it to the English front line were so exhausted that the English made quick work of them. That a smaller number of primarily longbowmen–peasants–with superior tactics could defeat so many brash and noble knights spelled the end of an era and foretold the shape of war to come.

The Art of War

If there is one lesson to be drawn from the thousand years of war contained in this book, it is how quickly the game changes. Weapons and tactics that prove effective for centuries can be overturned in a single battle by a new technology or approach. History is unsympathetic to those commanders who cling to old ways because of past success or a belief in their nobility. As in business and biology, you must adapt to survive.

1. In military terms, “heavy” here refers to the additional armor of the riders, not the obesity of the horses. ↩