"The Fertile Crescent is a region in the Middle East incorporating present-day Israel, West Bank, and Lebanon and parts of Jordan, Syria, Iraq and south-eastern Turkey. The term "Fertile Crescent" was coined by University of Chicago archeologist James Henry Breasted.
Watered by the Jordan, Euphrates and Tigris rivers and covering some 400-500,000 square kilometers with a population of 40-50 million, the region extends from the eastern shore of the Mediterranean Sea around the north of the Syrian Desert and through the Jazirah and Mesopotamia to the Persian Gulf.
The Fertile Crescent has an impressive record of past human activity. As well as possessing many sites with the skeletal and cultural remains of both pre-modern and early modern humans (e.g. at Kebara Cave in Israel), later Pleistocene hunter-gatherers and Epipalaeolithic semi-sedentary hunter-gatherers (the Natufians), this area is most famous for its sites related to the origins of agriculture. The western zone around the Jordan and upper Euphrates rivers gave rise to the first known Neolithic farming settlements (referred to as Pre-Pottery Neolithic A (PPNA)), which date to around 9,000 BC (and includes sites such as Jericho). This region, alongside Mesopotamia (which lies to the east of the Fertile Crescent, between the rivers Tigris and Euphrates), also saw the emergence of early complex societies during the succeeding Bronze Age. There is also early evidence from this region for writing, and the formation of state-level societies. This has earned the region the nickname "The Cradle of Civilization."
Since the Bronze Age, the region's natural fertility has been greatly extended by irrigation works, upon which much of its agricultural production continues to depend. The last two millennia have seen repeated cycles of decline and recovery as past works have fallen into disrepair through the replacement of states, to be replaced under their successors. Another ongoing problem has been salination - the seepage of salt water into irrigated farmland.
As crucial as rivers were to the rise of civilization in the Fertile Crescent, they were not the only factor in the area's precocity. The Fertile Crescent had a climate which encouraged the evolution of many annual plants, which produce more edible seeds than perennials, and the region's dramatic variety of elevation gave rise to many species of edible plants for early experiments in cultivation. Most importantly, the Fertile Crescent possessed the wild progenitors of the eight Neolithic founder crops important in early agriculture (i.e. wild progenitors to emmer, einkorn, barley, flax, chick pea, pea, lentil, bitter vetch), and four of the five most important species of domesticated animals - cows, goats, sheep, and pigs - and the fifth species, the horse, lived nearby."