Things You Didn't Know About Hitler That Will Blow Your Mind

In the early 13th century, Wanyan Yongji, mighty emperor of the Jin, sent a message to an upstart warlord who had the temperance to invade his territory. “Our empire is as vast as the sea,” it read. “Yours is but a handful of sand. How can we fear you?”

It was a bold statement, but one that was, on the face of it at least, fully justified. For the Jin dynasty of northern China was perhaps the most powerful polity on the face of the Earth at the time. The Jin had unimaginable wealth, gunpowder and an enormous army equipped with state-of-the-art weaponry, such as catapults. What’s more, they could call upon the protection of one of the foremost engineering feats of all time, the Great Wall of China. So why should they be concerned about a nomad army riding roughshod over their land? But there were a couple of problems.

The Jin weren't facing any old bunch of nomads, and the man commanding them wasn't any old leader. He was Genghis Khan. Over the next two decades, the Mongol ruler would forge a reputation as arguably the greatest military commander in history. And it was at the very heart of Wanyan Yongji’s empire – in the streets of his magnificent capital, Beijing – that he would announce himself to the world.

By the time his Mongol army first attacked Beijing in 1214, tens of thousands of hapless Chinese men, women and children had already become acquainted with Genghis Khan’s ‘talents’ as a brutal, destructive force. A few years earlier, he had launched a massive invasion of northwest China, pillaging, plundering and killing on an epic scale. Not even the Great Wall could stop him. Instead of attempting to assault it, he simply took his army around the side.

Now, having arrived at Beijing, Genghis Khan faced another wall, the one surrounding the city. It was 12 meters high, 10 miles long and bristling with defenders ready to rain down molten metals, crude oil, even excrement and poisons onto the Mongols. “I had trained my men to attack with the speed of the wind,” Genghis Khan recalled. “Now they had to learn the guile of the wolf.”