Battles are won by destroying an opponent's ability to fight - either by inflicting heavy casualties or frightening him off the field.
There are broadly two ways of doing it, each with appropriate weapons.
"Shock" tactics involve hand-to-hand assault which aims to break his ranks by the violence and moral effect of the charge.
"Missile" tactics shoot him down at a distance.
In the heyday of feudal cavalry it was the mounted charge ("shock")
which mostly decided battles. Missiles were little used because short-bow
archery and early cross-bows were too feeble or slow to shake a stubborn
passive defence. The impetus of heavy cavalry rarely failed against stationary
horsemen or infantry. But cavalry were of little use to defend a position
and to stand still was to surrender their main advantage of mobility and
weight. Battles tended to be simultaneous charges by both sides, followed
by a mêlée in which numbers or determination eventually told.
But once effective "missile" weapons came into use, the case altered.
It became possible to kill or dismount a charging enemy before he could
contact or so weaken and disorder his impact that the mounted charger could
be held by a line of dismounted men-at-arms. It should be remembered that
mailed cavalry relied on weight rather than speed. The equipment was heavy
and became heavier to meet the threat of arrows and their horses were no
racers but huge slow types. Also the longbow had a rate of fire that was
not equalled until the introduction of the breech-loading rifle.
It was the combination of archers with dismounted men-at-arms which
gave the English their victories over French cavalry, relying on shock
alone. But purely defensive tactics, however efficient can only win battles
if the enemy obliges by battering himself to pieces against them. They
leave him free to decide if and when to give battle and when to break it
Mostly medieval battles took the form of frontal attack. One side (generally
the weaker) choose a position with its flank protected by some obstacle
like a river, marsh or wood and if possible with a slope in front to lessen
the effect of the enemy charge,. The other deployed on the same frontage
and attacked and either broke through or was driven back. There was little
attempt at manoeuvre and surprisingly little use was made of outflanking
We can have sympathy with those medieval commanders who once the clash began, gave up all attempt at control and led charges instead. Encased in armour, amid indescribable noise, they had little opportunity to send orders or hear messages except during a lull. If they stayed in the rear they had more chance of seeing what was going on but little chance of getting orders through to men in the thick of mêlée. If they kept a reserve to throw in there was a danger of the front line being outflanked.