The term "cradle of civilization" refers to locations where, according to current archeological data, civilization is understood to have emerged.
Current thinking is that there was no single "cradle", but several civilizations that developed independently, with the Fertile Crescent (Mesopotamia and Ancient Egypt) understood to be the earliest. Other civilizations arose in Asia among cultures situated along large river valleys, such as the Indo-Gangetic Plain in Ancient India and the Yellow River in Ancient China. The extent to which there was significant influence between the early civilizations of the Near East and those of East Asia is disputed. Scholars accept that the civilizations of Mesoamerica, mainly in modern Mexico, and Norte Chico in present-day Peru emerged independently from those in Eurasia.
Scholars have defined civilization using various criteria such as the use of writing, cities, a class-based society, agriculture, animal husbandry, public buildings, metallurgy, and monumental architecture. The term cradle of civilization has frequently been applied to a variety of cultures and areas, in particular the Ancient Near Eastern Chalcolithic (Ubaid period) and Fertile Crescent, Ancient India and Ancient China. It has also been applied to ancient Anatolia, the Levant and Iranian plateau, and used to refer to culture predecessors such as Ancient Greece as the predecessor of Western civilization, even when such sites are not understood as an independent development of civilization, as well as within national rhetoric.
The earliest signs of a process leading to sedentary culture can be seen in the Levant to as early as 12,000 BC, when the Natufian culture became sedentary; it evolved into an agricultural society by 10,000 BC. The importance of water to safeguard an abundant and stable food supply, due to favourable conditions for hunting, fishing and gathering resources including cereals, provided an initial wide spectrum economy that triggered the creation of permanent villages.
Mesopotamia, the area between the Tigris and Euphrates Rivers (in modern day Iraq), is often referred to as the cradle of civilization because it is the first place where complex urban centers grew. The history of Mesopotamia, however, is inextricably tied to the greater region, which is comprised of the modern nations of Egypt, Iran, Syria, Jordan, Israel, Lebanon, the Gulf states and Turkey. We often refer to this region as the Near or Middle East.
Around 10,200 BC the first fully developed Neolithic cultures belonging to the phases Pre-Pottery Neolithic A (PPNA) and Pre-Pottery Neolithic B (7600 to 6000 BC) appeared in the Fertile Crescent and from there spread eastwards and westwards. One of the most notable PPNA settlements is Jericho in the Levant region, thought to be the world's first town (settled around 8500 BC and fortified around 6800 BC). In Mesopotamia, the convergence of the Tigris and Euphrates rivers produced rich fertile soil and a supply of water for irrigation. The civilizations that emerged around these rivers are among the earliest known non-nomadic agrarian societies. It is because of this that the Fertile Crescent region, and Mesopotamia in particular, are often referred to as the cradle of civilization.
The period known as the Ubaid period (c. 6500 to 3800 BC) is the earliest known period on the alluvial plain, although it is likely earlier periods exist obscured under the alluvium. It was during the Ubaid period that the movement towards urbanization began. Agriculture and animal husbandry were widely practiced in sedentary communities, particularly in Northern Mesopotamia, and intensive irrigated hydraulic agriculture began to be practiced in the south. Around 6000 BC, Neolithic settlements appear all over Egypt. Studies based on morphological, genetic and archaeological data have attributed these settlements to migrants from the Fertile Crescent in the Near East returning during the Egyptian and North African Neolithic, bringing agriculture to the region. Eridu is the oldest Sumerian site settled during this period, around 5300 BC, and the city of Ur also first dates to the end of this period. In the south, the Ubaid period had a very long duration from around 6500 to 3800 BC; when it is replaced by the Uruk period.