Orthodox mysticism was generated by experience derived from spiritual practices: monastic asceticism, military art, religious-oriented family building and political activity. The book of the historian, religious scholar, culturologist and publicist Roman Bagdasarov reveals the cosmology of Ancient Russia, the mystical foundations of the power of the aristocracy, "inner doing" and foolishness in Christ, the knightly attitudes of the Cossacks. Separate essays are devoted to the mysterious fate of Old Ryazan and St. Petersburg.