The first urban settlements are thought to have started around 3500BC in lower Mesopotamia (Sumer) around the Tigris and Euphrates. First was Ur, which from 2300 BC to 2180BC was the capital city of the Sumerian Kingdom, extending north along the Fertile Crescent, possibly as far as the Mediterranean. In the year 1885BC Ur and the other southern cities were captured by Babylonians.
An Important milestone in development of urban settlements were Zigurrat. Ziggurats were built by many civilizations namely Sumerians, Babylonians, Elamites, Akkadians, and Assyrians
There is still an open debate over whether it was diffusion or independent inventions but it is probable that agricultural and other advanced technologies, possibly including city-building, diffused across the Fertile Crescent, then south-west into the Nile valley. By 3500BC a number of the Neolithic farm hamlets along the lower Nile had expanded to ‘overgrown village’ status and formed clusters of several politically independent units, each containing sizeable irrigation projects like Qanat. The transition from settled agricultural communities to cities taken place around 3300 BC when the lower Nile region was unified by the first pharaoh, Menes. The early Egyptian cities were not as large and as densely populated as those of Mesopotamian cities because of the practice of changing the site of the capital, usually the largest settlement, with the succession of a new pharaoh limited the growth opportunity of any single city and the security provided by extensive desert on both sides of the Nile which meant that once the valley was unified politically, Egyptian cities, unlike those of Mesopotamia, did not require elaborate fortifications and garrisoned troops for protection.
The Indus Valley
The Harappa civilisation dates around 2500 BC in the Indus valley in present-day Pakistan. Twin famous capital cities distinguished it, a northern one of Harappa in the Punjab and Mohenjo-Daro, 500 km down the river. The Indus valley towns were planned and the layout of each town was in marked contrast to the organic growth of Mesopotamian cities such as Ur. Both cities were designed on a grid pattern with wide, straight streets forming rectangular blocks. Socio-spatial segregation was prevalent, with blocks or precincts occupied by a specific group such as potters, weavers, metalworkers and the elite. Each city covered approximately one square mile in area and accommodated around 20,000 people.
The Harappa kingdom was ruled from the twin capitals by a single ‘priest-king’ with absolute power in his hand . Some evidence of trade with the Sumerian city-states by 2000 BC are found but the unchanging material culture and still undeciphered written language suggest that, in contrast to the cities of the Nile valley, the Harappa culture and cities emerged on their own. Following a thousand years of stability, the Harappa civilization was phased out.
The Yellow River
The valley of the Huangho ,the Yellow River(Yellow in colour due to Loess) was the birthplace of the Shang civilisation that came into existence around 1800BC. The most significant feature is that individual cities, such as An-Yang, were linked into a network of agricultural villages; a town wall did not separate an urban subculture from a rural one. This form of ‘urban region’ is notably without precedent in the early civilisations of Mesopotamia, the Nile and the Indus.
The layout of the cities shared that of other ancient urban areas of Asia, similar to ones in Egypt and Mexico: a central core with the surrounding area divided into four regions, one for each of the cardinal directions.
The earliest cities in the New World appeared around 200 BC—in southern Mexico (Yucatan), Guatemala, Belize and Honduras. Thus Mesoamerican peoples were entering a stage of development equivalent to the Neolithic of the Old World at a time when Mesopotamian cities were 2,000 years old. Of the several civilisations that evolved in Mesoamerica, the Mayan, which flourished between AD 300 and AD 1000, was the most culturally advanced. Cities such as Tikal, Vaxactum and Mayapán were centres of small states ruled by a leader drawn from a priest-hood and organised into a loose confederation. Mesoamerican society was highly stratified, with the elite occupying central city land around the palaces and temples, and the lower classes occupying the periphery of urban settlement. City design was highly advanced.
Urban Geography: A Global Perspective Pacione 2e Pb – Pdf .., https://epdf.tips/urban-geography-a-global-perspective-pacione-2e-pb.html (accessed September 19, 2018).ly