Quoting Eric Margolis, Jones observes that in the 13th century the Mongol armies under Genghis Khan were genocidal killers [18] who were known to eradicate whole nations.[19] He ordered the extermination of the Tata Mongols, and all Kankalis males in Bukhara "taller than a wheel"[20] using a technique called measuring against the linchpin. In the end, half of the Mongol tribes were exterminated by Genghis Khan.[21] Rosanne Klass referred to the Mongols' rule of Afghanistan as "genocide".[22]