We introduce the Historical Attractor Theory (HAT), a foundational framework in which physical reality is defined at the level of complete histories rather than instantaneous states. Within this approach, realizability is determined by a global criterion of historical stability, encoded in a scalar functional that orders histories according to their degree of openness. Physical reality corresponds to histories that satisfy a strict closure condition, suppressing incompatible alternatives without invoking fundamental time, dynamical collapse, or observer-dependent postulates. Quantum, classical, thermodynamic, and geometric descriptions emerge as effective regimes operating within historically stabilized narratives. HAT provides a unified structural principle that reorganizes central problems in the foundations of physics by shifting the focus from state-based dynamics to global historical consistency.