{"method":"Benchmark periods are used so uncertain historical boundaries, cultural zones, population estimates, and event layers are not falsely presented as exact continuous annual reconstruction. The interface loads records by selected historical scene, period window, layer, and viewport.","periods":[{"atlas_focus":"early urban threshold","label":"Early urban worlds","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"First atlas frame for river-valley urban worlds; use it to compare early state formation, writing zones, and long-distance exchange beginnings.","scope":"Egypt, Mesopotamia, Indus and early state formation","year":-3000},{"label":"Bronze Age urban networks","scope":"Old Kingdom Egypt, Sumerian cities, Indus urbanism, early long-distance exchange","year":-2500},{"label":"Middle Bronze Age systems","scope":"Aegean, Anatolia, Mesopotamia, Egypt, Indus aftermath and early state networks","year":-2000},{"atlas_focus":"late bronze diplomatic system","label":"Late Bronze Age empires","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Composes New Kingdom Egypt, Hittite Anatolia, Mitanni, Mycenaean and Near Eastern exchange before the late Bronze Age rupture.","scope":"New Kingdom Egypt, Hittites, Mitanni, Mycenaean world and Near Eastern diplomacy","year":-1500},{"label":"Late Bronze Age transition","scope":"Eastern Mediterranean collapse, early Iron Age shifts and imperial reorganization","year":-1200},{"label":"Early Iron Age world","scope":"Neo-Assyrian expansion, Phoenician networks, Greek poleis, early kingdoms and steppe zones","year":-800},{"atlas_focus":"classical imperial comparison","label":"Classical world","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Shows Achaemenid, Greek, Indian and Chinese worlds as a comparative political-cultural scene rather than a single civilizational center.","scope":"Achaemenid, Greek, Indian, Chinese and Mediterranean worlds","year":-500},{"label":"Hellenistic and Mauryan age","scope":"Alexander's successors, Mauryan India, Mediterranean and Central Asian connections","year":-300},{"atlas_focus":"imperial afro-eurasian system","label":"Imperial ancient world","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Roman, Han, Parthian/Kushan and Indian Ocean layers should be read together as a connected ancient-world scene.","scope":"Roman, Han, Parthian and connected Afro-Eurasian routes","year":0},{"label":"High imperial antiquity","scope":"Roman, Han successor dynamics, Kushan routes and Indian Ocean exchange","year":200},{"label":"Late antique transition","scope":"post-Roman West, Byzantium, Sasanian world, Gupta aftermath","year":500},{"atlas_focus":"post-antique transformation","label":"Early medieval transformation","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Use this frame for the Byzantine-Sasanian aftermath, early Islamic expansion, Tang consolidation and late antique-to-medieval transition.","scope":"Byzantine-Sasanian aftermath, early Islamic expansion and Tang consolidation","year":650},{"label":"Early Islamic and Tang era","scope":"Abbasid, Tang, Byzantine, steppe and Indian Ocean systems","year":750},{"label":"Medieval regional worlds","scope":"Abbasid fragmentation, Byzantine recovery, European kingdoms, African and Asian states","year":900},{"label":"Medieval consolidation","scope":"Byzantium, Islamic worlds, Song China, medieval Europe, African states","year":1000},{"label":"Crusader and Song-era world","scope":"Crusades, Seljuk and Fatimid worlds, Song economy, Sahelian and Indian Ocean networks","year":1100},{"atlas_focus":"high medieval connected world","label":"High medieval world","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Best read as a routes-and-institutions scene: trade corridors, universities, cities, religious geographies and regional empires.","scope":"trade routes, universities, empires and religious geographies","year":1200},{"label":"Mongol expansion era","scope":"Eurasian campaigns, successor polities, Silk Road and steppe-imperial integration","year":1250},{"label":"Mongol and connected Eurasia","scope":"Mongol successor polities and transcontinental exchange","year":1300},{"label":"Late medieval world","scope":"Timurid, Ming, Ottoman, Mamluk, European and African political geographies","year":1400},{"label":"Late medieval / early oceanic transition","scope":"pre-Columbian Americas, Ottoman expansion, Ming, Indian Ocean","year":1450},{"atlas_focus":"early modern opening","label":"Early modern opening","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Bridge scene from late medieval political geographies to Atlantic, Indian Ocean and gunpowder-imperial systems.","scope":"Atlantic, Ottoman, Safavid, Mughal, Ming, European maritime expansion","year":1500},{"label":"Early modern empires","scope":"global maritime routes, gunpowder empires, colonial systems","year":1600},{"label":"Imperial competition","scope":"Atlantic empires, Eurasian states, trade companies","year":1700},{"label":"Pre-industrial global system","scope":"imperial rivalry, Atlantic exchange, Qing, Mughal successor states and trade corridors","year":1750},{"atlas_focus":"revolutionary imperial world","label":"Revolutionary and imperial world","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Useful for comparing Napoleonic-era Europe, colonial expansion, industrial transition and changing global transport/political systems.","scope":"Napoleonic era, colonial expansion, industrial transition","year":1800},{"label":"Industrial and imperial acceleration","scope":"railways, empires, population growth, reform states and global commodity networks","year":1850},{"label":"Modern international-system baseline","scope":"CShapes-compatible global state boundaries begin","year":1886},{"atlas_focus":"world war handoff","label":"First World War opening","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Global history frame intentionally hands off to the First World War Operational Atlas for operational detail.","scope":"AP WWI atlas handoff and global alliance geography","year":1914},{"atlas_focus":"second world war handoff","label":"Second World War opening","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Global history frame intentionally hands off to the Second World War Operational Atlas for operational detail.","scope":"AP WWII atlas handoff and global conflict geography","year":1939},{"atlas_focus":"postwar settlement","label":"Postwar settlement","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"Use this as the UN/decolonization baseline: wartime settlement, occupation, reconstruction and new international institutions.","scope":"UN order, decolonization baseline and postwar reconstruction","year":1945},{"label":"Decolonization world","scope":"African and Asian independence, Cold War alignments and development geographies","year":1960},{"atlas_focus":"post-cold-war transition","label":"Post-Soviet transition","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"State-system and conflict layers should be read as a transition scene after Soviet dissolution, not as a timeless contemporary map.","scope":"post-Cold War state system and new regional conflicts","year":1991},{"atlas_focus":"contemporary atlas frame","label":"Contemporary atlas frame","reading_note":"Benchmark period, not exact annual reconstruction; compare layer type, source status and geometry precision before reading claims.","scene_summary":"This frame connects current conflict, transport, displacement, disaster and Armenia-room atlas work into the modern AP Atlas system.","scope":"AP current conflict, transport, displacement and disaster layers","year":2026}],"title":"AP World History Atlas benchmark periods","version":"2026-06-29-world-history-atlas-periods-v2"}