The archetypal empire cycle maps to 18 sequential stages: the rise builds on education, innovation, and competitive discipline; the peak features strong income and financial dominance; the decline begins with productivity loss and overextension, progresses through wealth inequality and debt monetization, and terminates in internal conflict, loss of reserve currency, and potential civil war/revolution. For a quant: the debt monetization and reserve currency loss phases are tradeable — they correspond to currency debasement regimes, commodity outperformance, and bond underperformance.