Middle AgesTechnology Horse collar c. 900 CENotable A padded collar lets horses pull plows without choking, speeding up farming. ▲ 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 → Sheep and goats domesticated → Cattle domesticated → Ox-drawn plow → Heavy plow and crop rotation → Horse collar Community notesLoading notes… Learn more ranked by votesBookLynn White Jr.Medieval Technology and Social Change ↗Editor's pickVideoSearch on YouTubemedieval horse collar invention ↗Editor's pick