Khubilai and the Song

CHAPTER 10 · 1234–1279 · The Mongol Empire, 1206–1294

Song China was everything the steppe was not — and for forty-five years it was the conquest the machine could not finish. Look at the blue on your map: seventy million people, the world’s richest economy (paper money, blast furnaces, a merchant marine), no horse country anywhere, and a defense grid built of exactly what cavalry cannot eat: rivers, rice paddies, and walled cities provisioned by water. The Mongols’ first fifteen years of war (from 1234, the Song having helped kill the Jin — Chapter 3’s debt) win almost nothing; Möngke’s great three-front invasion of 1258–59 kills the Great Khan

The turn: Xiangyang, 1268–1273.

This chapter is one scene of an interactive atlas: the map repaints as the dates advance, campaigns draw themselves, and every chapter argues its causes and consequences — then a field exam asks you to prove it on the map.