Even the climate meant that there were strange (to the Mongols) diseases waiting to strike them down. The terrain was not best suited to the strategy and tactics of a fast-moving army based primarily on horse archers. Southern China was populous, rich and had a large number of strong-walled cities.

It was to prove a tough, long and hard-fought war. Mongke and Kublai set about a joint campaign of conquest against Sung China. A third brother, Hulegu, was given command of the Mongols in the Middle East, although this was never a primary concern for Great Khan and the invasion of Europe was never to be repeated. He also gave his brother Kublai a free choice of conquered territory in China. A grim warrior, Mongke immediately set the Mongols back on the path of conquest. Mongke, one of Genghis Khan's grandsons, eventually seized power and was proclaimed the Great Khan. It would take more than 40 years to defeat the Sung.But with Ogadai's death in 1241 (his excessive drinking finally killed him), the Mongol Empire looked like dissolving into a set of warring tribal groups. The Kingdom of the Sung, south of the Hwai River, was a Chinese nation: ancient, civilized and not a pushover. The ruling Chin, after all, were still steppe nomads at heart. It had taken hard campaigning by virtually the entire Mongol forces to destroy the last Chin province in the North in 1234. Resistance to the Mongols had stiffened immediately after Genghis Khan's death.

Total war genghis khan