Mongol conquests (1271): Yuan declared

Thirteenth-century conquests that built the largest contiguous land empire and left a death toll still argued in wide scholarly ranges. The Mongol conquests began as Temujin unified the steppe and took the title Chinggis (Genghis) Khan in 1206. Within two generations Mongol armies had broken the Jin and Western Xia, shattered Khwarezm, taken Kiev's political world, and ridden into Hungary and Poland (1241). The empire later split into khanates while Kublai Khan completed the conquest of Song China and founded the Yuan dynasty (1271).

Deaths are among the least certain in this atlas: published scholarly ranges often sit around 20-40 million across the thirteenth century, with some older figures higher and many local studies lower. Siege massacres (Baghdad 1258, Zhongdu, Nishapur in the chronicles) sit beside famine and displacement. Treat every total as a band, not a census.

The same empire that destroyed cities also ran relay posts (yam), protected some trade, and moved artisans and astronomers across Eurasia -- the "Pax Mongolica" of later textbooks. English memory arrives through Travels of Marco Polo, school maps of a pink-brown blob, and a thin film canon. Korean memory is more specific: the 1231-59 Goryeo wars and the forced 1274/1281 expeditions toward Japan.