20th century BC
(21st century BC - 20th century BC - 19th century BC - other centuries)(3rd millennium BC - 2nd millennium BC - 1st millennium BC)
Events:
- 2064 - 1986 BC -- Twin Dynasty wars in Egypt
- 1991 BC -- Egypt: End of Eleventh Dynasty, start of Twelfth Dynasty
- 1932 BC -- Amorite conquest of Ur
- 1913 - 1903 BC -- Egyptian-Nubian war
- 1900 BC -- Achaean invasions of Greece
- around 1900 BC -- Fall of last Sumerian dynasty
