Genghis Khan on Tax Policy: Oh, I Never Thought of That

Truth is, Genghis Khan didn't know the first thing about tax policy. The first thing being: don't kill the goose that lays the golden egg:

At the time of Jenghis Khan's last campaign in Kansu, a Mongol general pointed out to him tht his new Chinese subjects would be useless to him, since they were unsuited to warfare, and that therefore he would do better to exterminate them--there were nearly ten million--so that he might at least make use of the soil as grazing land for the cavalry. Jenghiz Khan appreciated the cogency of this advice, but Ye-lü Ch'u-ts'ai protested. "He explained to the Mongols, to whom any such idea was unknown, the advantage to be gained from fertile soil and hard-working subjects. He made clear that by imposing taxes on land and exacting tribute on merchandise, they might colect 500,000 ounces of silver yearly, 80,000 pieces of silk, and 400,000 sacks of grain." He won his point, and Jenghiz Khan ordered Ye-lü Ch'u-ts'ai to draw up a system of taxation on these lines.

--René Grousset, The Empire of the Steppes:

A History of Central Asia 251(English Trans. 1970)

Afterthought: Might be more correct to say that Genghis Khan understood tax policy well enough (or parasitology: don't kill the host); he just didn't understand settled peoples. By all accounts, Genghis Khan set foot in a city just once in his life (Bukhara, around 1221), and he didn't like it, and didn't stay--one is reminded of the Saudis coming to meet with Presidennt Roosevelt, and pitching their tents on shipboard.