Introduction; Part I. The Long Period: Some Milestones: 1. A Brief History of Long-run Economic Analysis; 2. Empirical Elements; Part II. Unified Growth Theory: Foundations: 3. The Stagnation Regime; 4. Economic Take-off; 5. Institutions and Distribution; 6. The Natural Environment; Part III. Unified Growth Theory: Microeconomics of Regime Shift: 7. Economic Growth and Education; 8. The Birth of Institutions; 9. Lifestyles and the Natural Environment; Conclusion. Continuity and Discontinuity in History.