Central Asia is the core region of the Asian continent and stretches from the Caspian Sea in the west to China in the east and from Afghanistan in the south to Russia in the north. It is also sometimes referred to as Middle Asia, and, colloquially, "the 'stans" (as the five countries generally considered to be within the region all have names ending with that suffix) and is within the scope of the wider Eurasian continent.

In modern contexts, all definitions of Central Asia include these five republics of the former Soviet Union: Kazakhstan (pop. 16.6 million), Kyrgyzstan (5.5 million), Tajikistan (7.6 million), Turkmenistan (5.1 million), and Uzbekistan (29.5 million), for a total population of 64.7 million as of 2012. Other areas included are Afghanistan, Pakistan, Mongolia, and sometimes Xinjiang and Tibet in western China and southern Siberia in eastern Russia.

Various definitions of its exact composition exist, and no one definition is universally accepted. Despite this uncertainty in defining borders, it does have some important overall characteristics. For one, Central Asia has historically been closely tied to its nomadic peoples and the Silk Road. As a result, it has acted as a crossroads for the movement of people, goods, and ideas between Europe, West Asia, South Asia, and East Asia.

Genghis Khan (/ˈɡɛŋɡɪs ˈkɑːn/ or /ˈdʒɛŋɡɪs ˈkɑːn/,Mongol: [tʃiŋɡɪs xaːŋ] ( listen); 1162? – August 1227), born Temujin, was the founder and Great Khan (emperor) of the Mongol Empire, which became the largest contiguous empire in history after his death.

He came to power by uniting many of the nomadic tribes of northeast Asia. After founding the Mongol Empire and being proclaimed "Genghis Khan", he started the Mongol invasions that resulted in the conquest of most of Eurasia. These included raids or invasions of the Kara-Khitan Khanate, Caucasus, Khwarezmid Empire, Western Xia and Jin dynasties. These campaigns were often accompanied by wholesale massacres of the civilian populations – especially in Khwarezmia. By the end of his life, the Mongol Empire occupied a substantial portion of Central Asia and China.

Before Genghis Khan died, he assigned Ögedei Khan as his successor and split his empire into khanates among his sons and grandsons. He died in 1227 after defeating the Western Xia. He was buried in an unmarked grave somewhere in Mongolia at an unknown location. His descendants went on to stretch the Mongol Empire across most of Eurasia by conquering or creating vassal states out of all of modern-day China, Korea, the Caucasus, Central Asian countries, and substantial portions of modern Eastern Europe, Russia and the Middle East. Many of these invasions resulted in the large-scale slaughter of local populations, which have given Genghis Khan and his empire a fearsome reputation in local histories.