Augustine provided the theoretical justification for medieval papal supremacy

Evidence

All through the Middle Ages, during the gradual rise of the papal power, and throughout the conflict between Pope and Emperor, St Augustine supplied the Western Church with the theoretical justification of its policy. — Bertrand Russell, History of Western Philosophy, 1432

Categorization

• corroborated: 2 independent passages support this claim — Bertrand Russell, History of Western Philosophy, 1432
• XREF: connects to: Roman imperial rule inspired the universalist ideology of the medieval church — Bertrand Russell, History of Western Philosophy, 1130; Even the papacy endorsed the African-barbarism racial worldview; Priestly celibacy deliberately severed local attachments and enabled papal absolutism — Georg Simmel, on individuality and social forms_…, 679