Bronze and Iron AgesGovernment & Law Indus Valley cities c. 2,600 BCEMajor Harappa and Mohenjo-daro have grid streets, drains and standardized weights. Their script is still undeciphered. ▲ 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 → Habitual fire and cooking → Homo sapiens appears → Complex language → Natufian villages → Oldest known bread → Agriculture begins → Mehrgarh → Indus Valley cities Community notesLoading notes… Learn more ranked by votesDocumentbritannica.comIndus civilization (Britannica) ↗Editor's pickBookJonathan Mark KenoyerAncient Cities of the Indus Valley Civilization ↗Editor's pickBookGregory L. PossehlThe Indus Civilization: A Contemporary Perspective ↗Editor's pickVideoSearch on YouTubeIndus Valley civilization explained ↗Editor's pick