Montesquieu publishes anonymously in Geneva in 1748 De l'esprit des lois. In Book XI, chapter 6, on the English constitution, he formulates that political liberty can only be preserved when legislative, executive, and judicial power rest in distinct bodies checking one another. Building explicitly on Locke, Montesquieu adds judicial independence and converts the distinction into an institutional requirement, influencing the US Constitution's three-branch architecture.