The attacker should ideally outnumber the defender by a ratio of at least three to one—or so the famed Prussian general Carl von Clausewitz wrote in his seminal work, On War.
It's a principle that has echoed through centuries not only those following the commander. The attacker, after all, bears the greater burden: advancing across uncertain ground, maintaining cohesion under fire, and gambling everything on a decisive breakthrough before exhaustion and confusion take their toll.
At Agincourt, the French learned this lesson the hard way. They marched through churned mud and uneven terrain, rain soaking their armor and clogging the earth beneath them. The English longbowmen waited with cruel patience, releasing volley after volley as the French forces, noble, proud, and heavily armored, bogged down in a mire of their own making. Their formation and cohesion had crumbled long before steel ever clashed with steel.
It was a clear truth: to attack meant to suffer first.
