Short answers, pulled from the story.
Genghis Khan was the founder and first khan of the Mongol Empire, born with the name Temujin into the Borjigin clan. He united the Mongol tribes and then conquered large parts of China and Central Asia. He adopted the title Genghis Khan at an assembly in 1206.
The year of Genghis Khan's birth is disputed between 1155, 1162, and 1167, with 1162 accepted by most historians. The Secret History records his birthplace as Deluun Boldog on the Onon River, debated between Dadal in Khentii Province and southern Agin-Buryat Okrug in Russia. His father was the chieftain Yesugei and his mother was Ho'elun.
Genghis Khan died on either the 18th or the 25th of August 1227 while subduing the rebellious Western Xia. He had fallen from his horse while hunting the previous winter and become increasingly ill. Sources variously suggest disease, an arrow, or lightning, and his death was kept a closely guarded secret.
Genghis Khan reorganised Mongol society into a military decimal system, conscripting every man between fifteen and seventy into a minqan, a unit of a thousand soldiers subdivided into hundreds and tens. He dispersed defeated tribes across different units to prevent rebellion and promoted commanders by merit and loyalty rather than birth. He also expanded his bodyguard, the keshig, from 1,150 to 10,000 men.
Genghis Khan invaded the Khwarazmian Empire in 1219 after its officials executed his merchants and envoys. Inalchuq, governor of Otrar, massacred a caravan of 450 traders as spies, and the ruler Muhammad killed the ambassador Genghis sent to avert war. The campaign toppled the Khwarazmian state and devastated Transoxiana and Khorasan.
Genghis Khan remains a controversial figure, remembered as a savage tyrant in Russia and the Arab world while honoured as the founding father of the nation in Mongolia. After the 1990 revolution, Mongolia renamed Lenin Avenue in Ulaanbaatar to Chinggis Khan Avenue, and his image now appears on banknotes, stamps, and many consumer brands. His conquests killed millions yet also enabled vast commercial and cultural exchange across Eurasia.