The Classical WorldWar & Conflict Great Wall begun 221 BCEMajor The Qin link earlier walls against northern nomads; later dynasties rebuild and extend them. ▲ MattersSaveShareTrace roots Longest chain: The Big Bang → First stars ignite → Supernovae seed heavy elements → The Sun forms → Earth forms → First oceans → First life → Photosynthesis evolves → Great Oxidation Event → Complex cells (eukaryotes) → Multicellular life → First animals → Cambrian Explosion → First vertebrates → Jawed fish → Fish walk onto land → The amniotic egg → The Great Dying → Dinosaurs appear → Asteroid ends the dinosaurs → Early primates → Apes split from monkeys → Human line splits from chimpanzees → Walking upright → First stone tools → Genus Homo appears → Homo erectus → Control of fire → First fired clay figures → First pottery → Copper smelting → Bronze Age begins → Shang dynasty → Zhou dynasty and the Mandate of Heaven → Spring and Autumn period → Legalism (Shang Yang) → Qin unifies China → Great Wall begun Community notesLoading notes… Learn more ranked by votesDocumentwhc.unesco.orgThe Great Wall (UNESCO World Heritage Centre) ↗Editor's pickDocumentbritannica.comGreat Wall of China (Britannica) ↗Editor's pickBookJulia LovellThe Great Wall: China Against the World ↗Editor's pickVideoSearch on YouTubeGreat Wall of China history ↗Editor's pick