Independent convergence
Astronomical record-keeping
Systematic observation and recording of celestial cycles, often tied to calendars.
26
civilizations with this trait
14
developed it with no documented contact with an earlier adopter
2,686 BCE
earliest known adopter: Old Kingdom Egypt
Timeline of adoption
Likely independent adoption Adopted after contact with an earlier adopter
Full list, earliest first
- Old Kingdom Egypt Nile Valley, North Africa 2,686 BCE – 2,181 BCE Independent
- Akkadian Empire Mesopotamia 2,334 BCE – 2,154 BCE Post-contact
- Old Babylonian Empire Mesopotamia 1,894 BCE – 1,595 BCE Independent
- Shang Dynasty Yellow River Valley, East Asia 1,600 BCE – 1,046 BCE Independent
- Egyptian New Kingdom Nile Valley and Levant 1,550 BCE – 1,077 BCE Post-contact
- Olmec Civilization Gulf Coast, Mesoamerica 1,500 BCE – 400 BCE Independent
- Vedic Civilization Northern Indian subcontinent 1,500 BCE – 500 BCE Independent
- Phoenician City-States Levantine coast 1,200 BCE – 539 BCE Post-contact
- Neo-Assyrian Empire Mesopotamia and the Near East 911 BCE – 609 BCE Post-contact
- Etruscan Civilization Central Italy 900 BCE – 27 BCE Independent
- Achaemenid Persian Empire Iranian Plateau to the Indus 550 BCE – 330 BCE Post-contact
- Classical Athens Attica, Greece 508 BCE – 322 BCE Post-contact
- Parthian Empire Iranian Plateau to Mesopotamia 247 BCE – 224 CE Independent
- Qin Dynasty Yellow River to Yangtze, East Asia 221 BCE – 206 BCE Independent
- Han Dynasty East Asia 206 BCE – 220 CE Post-contact
- Nazca Culture Southern coast, Peru 100 BCE – 800 CE Independent
- Teotihuacan Central Mexico 100 BCE – 550 CE Independent
- Roman Empire Mediterranean basin and Western Europe 27 BCE – 476 CE Post-contact
- Sassanid Empire Iranian Plateau and Mesopotamia 224 CE – 651 CE Post-contact
- Classic Maya Civilization Yucatán Peninsula and Central America 250 CE – 900 CE Post-contact
- Gupta Empire Northern Indian subcontinent 320 CE – 550 CE Independent
- Byzantine Empire Eastern Mediterranean and Anatolia 330 CE – 1453 CE Post-contact
- Khmer Empire Southeast Asia 802 CE – 1431 CE Independent
- Postclassic Maya (Chichén Itzá era) Northern Yucatán 900 CE – 1524 CE Post-contact
- Aztec (Mexica) Empire Central Mexico 1428 CE – 1521 CE Independent
- Inca Empire Andean South America 1438 CE – 1533 CE Independent