History of Sumer

The history of Sumer from Prehistoric Ubaid & Uruk Periods, spanned over a time of 3000 years-beginning with the first settlement at Eridu,( 5th-3rd Milleninnia) Enki’s main City, and ending with the downfall of the Third dynasty of Ur(around 2004BCE). Between that time and the rise of Babylon i.e. more a transition period of Amorite, Until the early rise of Babylonia in the early 2nd Millennium BC.
Situated in southern Mespotamia (modern day Iraq). It is, indeed, believed to be the earliest known civilization in the world, baring the name “Cradle of civilization”.
The Sumerian city states rose to power during the prehistoric Ubaid & Uruk periods. The history of Sumer reaches back to the 26th century BC, but records of anything earlier remains obscure until early Dynastic III Period,ca.
Classic Sumer ends with the rise of Akkad ( Akkadian Empire), in the 23rd century BC.
Ref: http://bruceowen.com/emciv/341-06f-12-EarlyDynastic.pdf

Situated between the Tigiris and Euphrates, upon the fertile crescent by 5000BCE the Sumerians were able to develop core agricultural techniques , including cultivation of land, organized irrigation and monocropping. The Sumerians managed to adopt agricultural way of life, which depended heavily upon irrigation- this was mastered by the use of shadufs, canals, channels, dykes, weirs asd reservoirs.
From 2600BCE on ward, the Sumerians could write multiplication tables on clay tablets and deal with geometrical exercises and division problems. 2700-2300BCE saw the first appearances of the Abacus (a tablet placed horizontally on top of the capital of a column as an aid in supporting the architrave). The Sumerians were, indeed, the first to use a place value numeral system,find the area of a triangle and the volume of a cube.

Such creations and examples of Sumerian technology are as follows: Cuneiform ,arithmetic and geometry, irrigation systems, Sumerian Boats, lunarsolar calendar, bronze, leather, saws, chisels, hammers, nails, pins, rings, hoes, axes, knives, arrowheads, swords, glue, daggers, waterskins, bags, harnesses, armour, quivers, war chariots, scabbards, sandals, boots, harpoons,Beer, (other:Astronomy,Astrology,granary).
The constant wars between neighbouring Sumerian city states helped develop the military technology and techniques to a higher level . The first war recorded in history was between Lagash and Umma ca.2525 BC sat 18 miles apart and feuded for generations over the fertile region known as Gu'edena. In 2525, King Eannatum of Lagash defeated Umma using armored soldiers in phalanx formations, and chariots pulled by onagers (wild asses), an invention frequently credited to the Sumerians .