We rented Mongol: The Rise of Genghis Khan, which presented the conqueror in a fairly favorable light, at least as far as it goes through the early stages of his career. This inspired me to reread parts of books I'd read long ago: On the Other Side: a Journey Through Soviet Central Asia, by Geoffrey Moorhouse, which looks at ruins left by the Mongols and sees aggression stemming from evil, and Khubilai Khan: His Life and Times, by Morris Rossabi, which depicts the Mongols, including the title subject's grandfather Genghis, as surprisingly tolerant and benevolent rulers, albeit granted they were aggressive when resisted.
Moreover, the second book gives impersonal reasons, including some of climate change, for why the Mongols expanded, whereas the first sees it as pivoting on one man who wanted to take revenge upon the world for his father's death and his clan's betrayal. Where the truth lies I will not guess, but I was fascinated by Rossabi's passing comment that one consequence of the Mongol expansion was to elicit interest in Europe in trade with Asia, thus spurring Europe's age of exploration.
