Power concentrated in one person can override institutional checks. A dictatorship is a form of government in which a single ruler or small group holds absolute authority, unconstrained by effective constitutional limits or regular free elections.

Ancient Rome appointed temporary dictators in emergencies; modern dictatorships have often claimed permanent authority. They may arise from military coups, revolutionary movements, or the erosion of previously democratic systems. Propaganda, surveillance, and repression of opposition typically sustain them.

Historians distinguish personalist dictatorships, party-based systems, and military regimes, each with different patterns of recruitment and succession. Economic performance and popular support vary widely. The study of dictatorships illuminates both the mechanisms of authoritarian control and the conditions under which such systems weaken or collapse.

• Rule by a single person or small group with absolute power
• Lacks effective constitutional constraints
• Maintained through coercion and propaganda
• Takes varied institutional forms