Antoine Favreau was a young cuirassier at Waterloo in 1815, taking part in one of the grandest cavalry defeats of all time, when a cannonball killed him instantly. Favreau could not have imagined the internet, or Twitter, or that two centuries after his death a Turkish academic would accidentally send a viral tweet about his cuirass (breastplate).
Of course, there were silly and hilarious reactions to the word “wounded” being used in this context. My serious point, however, is that Favreau’s devastated breastplate serves as an excellent demonstration of a key principle for studying military revolutions: firepower always defeats armor over time.
A human body simply cannot wear a suit of armor that would protect them from a cannon; it would weigh literal tons. Humans are simply better at imparting lethal energies than material physics is at stopping them. The compound bow defeated light bronze armors, necessitating heavier breastplates. The crossbow defeated early, thin steel armors, so breastplates thickened and steel quality improved. Handguns soon became reliable and powerful enough to penetrate cheap steel, and cannons were impossible to stop.
Thus, the unarmored soldier was frequently able to defeat the armored soldier while costing less, and after the 15th Century this was always to be the case. As you might expect, the cavalier class in Western Europe resisted these changes. One sign of this is how long armor lasted on horseback. Cavalry being more expensive than infantry in every era, armor had become a kind of status symbol for Napoleon’s cuirassier.
Which is not to say it was worn entirely without rational justification. The breastplate was helpful against the close-in threats of saber-cuts and bayonets that cavaliers are supposed to seek out. No one tried to convince Favreau that his armor was proof against bullets or cannonballs, nor was it just a show of equestrian class values.
However, by that point almost everyone else on the battlefield had given up on body armor because it was no longer economical in terms of money or energy. There was no reason for the state to provide it. Individual foot soldiers did not want to pay for quality steel armor, and it was another heavy thing to carry on the march, anyway. So if it was not effective against bullets or cannonballs — the chief threats foot soldiers faced as the 17th Century progressed, and pikes gave way to bayonets — why bother? Call it the wisdom of crowds.
