City and trade

Agriculture also created, and allowed for the storage of, food surpluses that could support people not directly engaged in food production. The development of agriculture permitted the creation of the first cities. These were centers of trade, manufacture and political power with nearly no agricultural production of their own. Cities established a symbiosis with their surrounding countrysides, absorbing agricultural products and providing, in return, manufactures and varying degrees of military protection.
The development of cities equated, both etymologically and in fact, with the rise of civilization itself: first Sumerian civilization, in lower Mesopotamia (3500 BCE), followed by Egyptian civilization along the Nile (3300 BCE) and Harappan civilization in the Indus Valley (3300 BCE). Elaborate cities grew up, with high levels of social and economic complexity. Each of these civilizations was so different from the others that they almost certainly originated independently. It was at this time, and due to the needs of cities, that writing and extensive trade were introduced.
The earliest known form of writing was cuneiform script, created by the Sumerians from ca. 3000 BC. Cuneiform writing began as a system of pictographs. Over time, the pictorial representations became simplified and more abstract. Cuneiforms were written on clay tablets, on which symbols were drawn with a blunt reed for a stylus. The first alphabets were used in the Middle Bronze Age (2000-1500 BCE). From them evolved the Phoenician alphabet, used for the writing of Phoenician. The Phoenician alphabet is the ancestor of many of the writing systems used today.
In China, proto-urban societies may have developed from 2500 BCE, but the first dynasty to be identified by archeology is the Shang Dynasty.
The 2nd millennium BCE saw the emergence of civilization in Caanan, Crete, mainland Greece, and central Turkey.

Trading routes used around the 1st century CE were centered on the Silk Road.
In the Americas, civilizations such as the Maya, Zapotec, Moche, and Nazca emerged in Mesoamerica and Peru at the end of the 1st millennium BCE.
The world's first coinage was introduced around 625 BC in Lydia (western Anatolia, in modern Turkey).[6]
Trade routes appeared in the eastern Mediterranean in the 4th millennium BCE. Long-range trade routes first appeared in the 3rd millennium BCE, when Sumerians in Mesopotamia traded with the Harappan civilization of the Indus Valley. The Silk Road between China and Syria began in the 2nd millennium BCE. Cities in Central Asia and Persia were major crossroads of these trade routes. Silla dynastic tombs have been found in Korea, containing relics such as wine cups produced in Iran.[7] The Phoenician and Greek civilizations founded trade-based empires in the Mediterranean basin in the 1st millennium BCE.
In the late 1st millennium CE and early 2nd millennium CE, the Arabs dominated the trade routes in the Indian Ocean, East Asia, and the Sahara. In the late 1st millennium, Arabs and Jews dominated trade in the Mediterranean. In the early 2nd millennium, Italians took over this role, and Flemish and German cities were at the center of trade routes in northern Europe controlled by the Hanseatic League. In all areas, major cities developed at crossroads along trade routes.