21st century BC

The 21st century BC was a century which lasted from the year 2100 BC to 2001 BC.

Events
Ur-Nammu (seated) bestows governorship on Ḫašḫamer, patesi (high priest) of Iškun-Sin (cylinder seal impression, ca. 2100 BC). Note: all dates from this long ago should be regarded as either approximate or conjectural; there are no absolutely certain dates, and multiple competing reconstructed chronologies, for this time period.

c. 2100 BC - Sintashta culture emerges; possible date when Proto-Indo-Iranian was spoken. c. 2100 BC – c. 2050 BC: Nanna Ziggurat, Ur (modern Muqaiyir, Iraq) was built. 2091 BC: Beginning of the Patriarchal Age was traditionally set in this year. 2080 BC: Ninth Dynasty wars in Egypt. 2080 BC: First Intermediate Period of Egypt ended. Middle Kingdom began in Ancient Egypt. 2071 BC: Magh Ithe, first recorded battle in Ireland myths. c. 2064 BC – 1986 BC: Twin Dynasty wars in Egypt. c. 2055 BC: End of First Intermediate Period of Egypt. Start of Middle Kingdom. (another date is 2040 BC). c. 2055 BC: Mentuhotep II from Thebes managed to reunite Ancient Egypt and began to rule (other date is 2040 BC). c. 2055 BC – 1985 BC: Funerary Stele of Amenemhat I was made. Eleventh Dynasty of Egypt. Excavated in 1915–1916. It is now kept in Egyptian Museum, Cairo. The Metropolitan Museum of Art, New York. c. 2050 BC: Eruption of Mt. Mariveles in the Philippines. c. 2049 BC: Oak trees for Seahenge felled. 2034 BC – 2004 BC: Ur–Amorite wars 2025 BC: The Old Assyrian Empire is established. Assur becomes the capital of the kingdom and remains so for almost 270 years. c. 2009 BC – 1997 BC: Funerary temple of Mentuhotep III was built. Eleventh Dynasty. 2004 BC: Elamite destruction of Ur. Third Dynasty of Ur disestablished. c. 2000 BC: Aegean Bronze Age ended.

Significant people
Although many human societies were literate in this period, some individual persons mentioned in this article ought to be considered legendary rather than historical.

Mentuhotep II Ur-Nammu, 3rd dynasty of Ur Shulgi of Urim Abraham

== Legendary people==

According to Abrahamic religious tradition, this was the era of the Patriarch Abraham (however, other datings include 19th century BC, and/or 17th century through 15th century BC) Inventions, discoveries, introductions 2100 BC—Earliest extant law code in Mesopotamia, the Code of Ur-Nammu