A keep with a full granary and no water is a locked pantry

The first man to say the gate would hold had never stood beneath it. Once every lord has a wall, a wall is for making the enemy spend a day, a cartload, or a regiment to reach what lies behind it. It is not the prize. The stores are the prize, and the road that feeds them decides how long the stone matters.

A keep with a full granary and no water is a locked pantry. A keep with water, but no road by which to bring in grain, is a promise that will sour by winter. The wall changes the price of reaching those things. It does not change the price of keeping them.

This is why the map matters more after every village is fortified. Before, a road led to a place. Now it leads to a gate, and the gate may be shut while the road behind it is cut. A column can march past a small fort, but it cannot make the fort’s men disappear. They can burn a bridge, take a cart, or ride out at night against the wagons. The enemy has left a wall behind him. The wall has left enemies behind him.

That is a useful bargain only if someone can feed the men inside. Otherwise the garrison is not holding a road. It is eating the provisions that should have gone to the field army, and waiting for the day it must either surrender or be relieved. Two carts. No fire. A commander who cannot name what those carts carry should not promise to hold the keep.

The wall also forces a choice on the people who built it. They may bring their food inside when danger comes, or leave it in barns where a raiding party can take it. They may bring their families, too. Then the courtyard fills, the well draws down, and every mouth becomes part of the defense plan. A gate can keep a raider out. It can also keep a hungry crowd from reaching the fields.

There is no shame in leaving a place that cannot be supplied. There is shame in leaving too late, when the carts are gone and the animals have been eaten, and the commander is still calling the delay courage. I learned that at Stonewatch. Three mules, forty-two men, and the chapel bell left behind because its rope had frozen to the tower. We could carry only what the road could bear. The bell was not worth a man’s back. It was still hard to hear it ring for the last time.

When every lord has a wall, the useful advantage belongs to the one who can choose what not to defend. A wall holds a place while the rest of the army moves, or buys enough time to empty the storehouse, or makes the enemy take the long road around. It can do one of these well. It cannot do all of them at once.

The wall is a measure of what a lord is willing to leave behind. Count the carts before you count the stones. Then count the road twice. The road is the danger. The road decides the march.