The doctrine of separation of powers was developed by political philosopher Montesquieu in the 18th century. It advocates for the division of government responsibilities into distinct branches: legislative, executive, and judicial. This separation is designed to prevent any one branch from gaining excessive power, thereby ensuring a system of checks and balances. By distributing authority across these branches, the doctrine aims to protect against tyranny and uphold individual liberties. Its adoption in various democratic systems has significantly influenced governance and the rule of law throughout modern history.