Genghis Khan? Or Chinggis Khaan? Maybe Khagan? History's most famous conqueror kept many secrets. Yet with some clever linguistic investigation, we can reanimate the sounds of his language.
Our journey starts with a Mongolian grammar and a trip to modern Mongolia, a language with some standout features. You'll see the Khan's name written everywhere... but in the Cyrillic script. Cross the border to Inner Mongolia in China to see everyday use of a much older script, a script with extra "hidden" syllables.
We'll trace those syllables back to when the soon-to-be-Khan, Temüjin, conquered the Naiman and encouraged his dignitaries to use the newfound Uyghur script. That Written Mongol has some archaic features, and comes from the time of the Khan, but another piece of evidence suggests it's too archaic.
In the 1800s, a scholarly Russian monk found a history book in China. It was written in Hànzì (Chinese characters), but the text didn't read well... unless you pronounced it in Mongolian. This turned out to be the Secret History of the Mongols. The language of the text was similar to Written Mongol, but it had notable differences, including modern-looking features. Still, it also seemed to come from the Khan's time. Was this Middle Mongol more authentic?
That's when we'll run into a third line of evidence: linguists comparing Mongolic languages and reconstructing Proto-Mongolic. There's not just one modern Mongolian; there's an entire Mongolic family. The features of this reconstructed proto-language matched the slightly modern-looking Middle Mongol.
In the end, these three ways of looking back to the early Mongols situate the Khan in linguistic history. Before him, there were Turkic loans (including the Khahan, the state "ulus", and the hero "baatur" in Ulaanbaatar), maybe dialects, and perhaps sibling Para-Mongolic languages. After him, a diversification into the modern languages. Between those, he unified his people and, in a "linguistic bottleneck", created a common Mongol language that turned into a language family in a relatively short time.
