Central Asia is one of the most landlocked regions on earth. The history of the region has been dramatically influenced by the lack of access to the sea and the dominance of nomadic culture. It has been the source of several major migrations and changing patterns in history. While the region is usually defined as being between the Tibetan mountain ranges and the Caspian Sea, the area of the region adjacent to Europe and the Black Sea demonstrates similar patterns of history with disproportionate influence on several regions in a variety of directions. Prior to the beginnings of recorded history, the region is thought to have mainly been Persian. About 4,000 years ago, a pattern of migration marked the entrance of peoples into the area of modern Iran, Pakistan and India. Presumed migrations from the same region toward Europe might explain a common origin for most of the two regions' languages, comprising part of the great Indo-European family of languages. Alternatively, massive migrations might have started even earlier, anywhere from 7,000-10,000 years ago. This theory is related to the hypothesis that the Black Sea region was once drier that now and that a sudden flooding of the area through the Bosphorus led to a massive evacuation of peoples in several directions.
From the 5th through 10th centuries CE, the inward migration of Turkic peoples changed the composition of the region, and such influence remains dominant today. These groups are related ethnically and culturally to the Mongols, who would later be political rivals, in the migrations that followed the rise of Islam. In the 7th century, Arab armies of the Islamic Caliphate began a push into the region north of Afghanistan, into Transoxania, but were unable to conquer any of it. They met fierce resistance from the shaminist Turks whose style of warfare was more suited for the steppes than was that of the Arabs. But a number of wars and patterns of raids would plague the region for centuries, resulting in the kidnapping and enslavement of many of the region's inhabitants by Muslims. Concomitantly, Turkic groups began their own raids and migrations southward. The combination of the latter with the elevation of the slaves to privileged status in the army or bureaucracy gradually gave a Turkic tint to the Islamic empires. A series of Turkic provinces and principalities developed, but Turkic dynasties also attained the thrones of major Islamic empires. Some Muslim commentators have suggested the rise of the Turks was meant to replace a decaying and corrupt Arab order and unsuitable Persian order. Thus suggestion grew from the realization of the relative stability the Turkic dynasties provided and the staying power of their dynasties.
The first of the great Turkic empires was under the Ghaznavids in Persia, ruling from the 10th through 12th centuries. In the 13th century, Genghis Khan launched a series of successful wars and, together with the strength of his grandson, encompassed the largest empire in human history, from China to Anatolia. The Uyghurs, Khazars, Avars and Uzbeks figured prominently while the Timurid Dynasty, the Mamluks of Egypt and the Mongol Ilkhanate ruled from Egypt to China during the 15th century. Turkic and Mongol dynasties maintained control of most of Asia through the 16th century. With the rise of the Safavids in Persia, the Ottoman Empire rose from an isolated Turkic principality in Anatolia. Following centuries of infighting, the Russian Empire expanded to encompass the region or at least exert unparalleled influence on it. Simultaneously, the Qing Dynasty whose origins were found in the eastern part of China, rose along the Central Asian Steppes. Russia gradually expanded its influence and moved in its own native residents, appropriating lands for Russians. World War I and the Russian Revolution gave a window for political nationalists to push their regions to independence. This did not last long, as communists and Russian forces asserted themselves and overran the nationalists. The spread of communism pushed hard into Mongolia as well. Internal Chinese politics was also impacted by Turkic nationalists who also met there with mixed success.
Following the fall of the Soviet Union, partly thanks to the failed effort to pacify Afghanistan, many Soviet republics in the area declared independence. Since then, there has been an expansion of influence from the United States.