Editing Asia (section)

=== Ancient era ===
{{See also|Sinosphere|Greater India|Greater Iran}}[[File:Silkroutes.jpg|thumb|upright=1.2|The [[Silk Road]] connected civilisations across Asia.<ref>{{cite web |author=Lee |first=Adela C. Y. |title=Ancient Silk Road Travellers |url=http://www.silk-road.com/artl/srtravelmain.shtml |url-status=live |archive-url=https://web.archive.org/web/20171108022054/http://www.silk-road.com/artl/srtravelmain.shtml |archive-date=8 November 2017 |access-date=9 November 2017 |website=Silk-road.com |publisher=Silkroad Foundation}}</ref>]]The history of Asia can be seen as the distinct histories of several peripheral coastal regions: [[East Asia]], [[South Asia]], [[Southeast Asia]], [[Central Asia]], and [[West Asia]]. The coastal periphery was home to some of the world's earliest known civilisations, each of them developing around fertile river valleys. The civilisations in [[Mesopotamia]], the [[Indus Valley]] and the [[Yellow River]] shared many similarities. These civilisations may well have exchanged technologies and ideas such as [[mathematics]] and the [[wheel]]. Other innovations, such as writing, seem to have been developed individually in each area. Cities, states and empires developed in these lowlands.

The central steppe region had long been inhabited by horse-mounted nomads who could reach all areas of Asia from the [[steppe]]s. The earliest postulated expansion out of the steppe is that of the [[Indo-Europeans]], who spread their languages into West Asia, South Asia, and the borders of China, where the [[Tocharians]] resided. The northernmost part of Asia, including much of [[Siberia]], was largely inaccessible to the steppe nomads, owing to the dense forests, climate and [[tundra]]. These areas remained very sparsely populated.

The center and the peripheries were mostly kept separated by mountains and deserts. The [[Caucasus]] and [[Himalaya]] mountains and the [[Karakum Desert|Karakum]] and [[Gobi]] deserts formed barriers that the steppe horsemen could cross only with difficulty. While the urban city dwellers were more advanced technologically and socially, in many cases they could do little in a military aspect to defend against the mounted hordes of the steppe. However, the lowlands did not have enough open grasslands to support a large equestrian force; for this and other reasons, the nomads who conquered states in China, India, and the Middle East often found themselves adapting to the local, more affluent societies.