“A prince should have no aim, no thought, and take up no art but war, its rules and its discipline; for that is the only art expected of a man who commands.” — Niccolò Machiavelli

None of your challenges are new. Great men faced them long ago, with their lives on the line. What they learned was written down — and then, for the most part, forgotten.

Now you can learn what they left behind.

The Ancient Laws of War is a curated collection of one hundred lessons on conflict and power. Each was paid for in blood by an accomplished commander, statesman, or philosopher — some famous, many forgotten.

The lessons span two thousand years and are organized into four parts: the self, the enemy, the battle, and power. Each line is paired with its verified source and a short explanation of what it means and how to use it. Read it front to back, or open it to any single entry before you need it.

1. The most aggressive commander in Europe admitted he was a coward at the planning table — and what he did with every danger before he moved.
2. The Roman commander who said that if his own shirt knew his battle plan, he would burn it.
3. Why retreat drains the courage out of brave men, and attack manufactures it even in a coward.
4. Who sees you more clearly than you see yourself — and why an enemy’s read of you is worth more than a friend’s.
5. The exact size of a favor at which a man stops being grateful and starts being your enemy.
6. The single point in any contest you should trust least — it arrives the moment everything is finally going your way.
7. The only two forces that truly bind men to you. Everything else is decoration.
8. Where power actually sits in any organization, no matter whose name is on the door.