Genghis Khan[note 4] (born Temüjin;[note 1] c. 1162 – August 25, 1227)[note 2][3] was the founder and first 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, and, after being proclaimed the universal ruler of the Mongols, or Genghis Khan, he set in motion the Mongol invasions, which ultimately conquered much of Eurasia, and witnessed raiding as far west as Legnica in western Poland and as far south as Gaza. During his life, he launched campaigns against the Qara Khitai, Khwarezmia, the Western Xia and Jin dyansty, while his generals raided into medieval Georgia, Circassia, the Kievan Rus', and Volga Bulgaria.
Genghis Khan and his empire have a fearsome reputation in local histories.[10] Many medieval chroniclers and modern historians describe Genghis Khan's conquests as wholesale destruction on an unprecedented scale, causing great demographic changes and a drastic decline of population as a result of mass exterminations and famine. A conservative estimate amounts to about four million civilians (whereas other figures range from forty to sixty million) who died as a consequence of Genghis Khan's military campaigns.[11][12][13][14] In contrast, Buddhist Uyghurs of the kingdom of Qocho, who willingly left the Qara Khitai empire to become Mongol vassals, viewed him as a liberator. Genghis Khan was also portrayed positively by early Renaissance sources out of respect for the great spread of culture, technology and ideas along the Silk Road under the Mongol Empire.[15] By the end of the Great Khan's life, the Mongol Empire occupied a substantial portion of Central Asia and China. Due to his exceptional military successes, Genghis Khan is often considered to be one of the greatest conquerors of all time.[16]
Beyond his military accomplishments, Genghis Khan also advanced the Mongol Empire in other ways. He adopted the Uyghur script as the Mongol Empire's writing system, maintained the strict but fair rule of Mongol law across his vast territories, practised meritocracy and encouraged religious tolerance. Present-day Mongolians regard him as the founding father of Mongolia for unifying the nomadic tribes of Northeast Asia.[17] His bringing the Silk Road under one cohesive political environment also considerably eased communication and trade between Northeast Asia, Muslim Southwest Asia, and Christian Europe, boosting global commerce and expanding the cultural horizons of all the Eurasian civilizations of the day.[18]
According to the Secret History, Temüjin was named after the Tatar chief Temüjin-üge whom his father had just captured. The name Temüjin is also equated with the Turco-Mongol temürči(n), "blacksmith", and there existed a tradition that viewed Genghis Khan as a smith, according to Paul Pelliot, which, though unfounded, was well established by the middle of the 13th century.[19]
The honorary title Genghis Khan is possibly derived from the Turkic tengiz, meaning sea,[20] making his title literally "oceanic ruler", interpreted figuratively as "universal ruler".[21] Genghis Khan is spelled in a variety of ways in different languages such as Mongolian Chinggis Khaan, English Chinghiz, Chinghis, and Chingiz, Chinese: 成吉思汗; pinyin: Chéngjísī Hán, Turkic: Cengiz Han, Çingiz Xan, Chingizxon, Shın'g'ısxan, Çingiz Han, Çıñğız Xan, Şıñğıs xan, Çiñğiz Xaan, Çiñğizhan, Russian: Чингисхан (Čingiskhan) or Чингиз-хан (Čingiz-khan), etc. Temüjin is written in Chinese as simplified Chinese: 铁木真; traditional Chinese: 鐵木眞; pinyin: Tiěmùzhēn.