Podcast with John Man, author of “Conquering the North: China, Russia, Mongolia: 2,000 Years of Conflict”
China, famously, built the Great Wall to defend against nomadic groups from the Eurasian steppe. For two millennia, China interacted with groups from the north: The Xiongnu, the Mongols, the Manchus, and the Russians. They defended against raids, got invaded by the north, and tried to launch diplomatic relations.