prevail and North China to become a country of pasturage, or was the country to keep to the agrarian tradition of the people under this rule?  The Turkish and Mongol conquerors had recently given up their old supplementary agriculture and had turned into pure nomads, obtaining the agricultural produce they needed by raiding or trade.  The conquerors of North China were now faced with a different question:  if they were to remain nomads, they must either drive the peasants into the south, or make them into slave herdsmen, or exterminate them.  There was one more possibility:  they might install themselves as a ruling upper class, as nobles over the subjugated native peasants.  The same question was faced much later by the Mongols, and at first they answered it differently from the peoples of our present period.  Only by attention to this problem shall we be in a position to explain why the rule of the Turkish peoples did not last, why these peoples were gradually absorbed and disappeared.

2 Status of the two southern Kingdoms

When the last emperor of the Han period had to abdicate in favour of Ts’ao P’ei and the Wei dynasty began, China was in no way a unified realm.  Almost immediately, in 221, two other army commanders, who had long been independent, declared themselves emperors.  In the south-west of China, in the present province of Szechwan, the Shu Han dynasty was founded in this way, and in the south-east, in the region of the present Nanking, the Wu dynasty.

The situation of the southern kingdom of Shu Han (221-263) corresponded more or less to that of the Chungking regime in the Second World War.  West of it the high Tibetan mountains towered up; there was very little reason to fear any major attack from that direction.  In the north and east the realm was also protected by difficult mountain country.  The south lay relatively open, but at that time there were few Chinese living there, but only natives with a relatively low civilization.  The kingdom could only be seriously attacked from two corners—­through the north-west, where there was a negotiable plateau, between the Ch’in-ling mountains in the north and the Tibetan mountains in the west, a plateau inhabited by fairly highly developed Tibetan tribes; and secondly through the south-east corner, where it would be possible to penetrate up the Yangtze.  There was in fact incessant fighting at both these dangerous corners.

Economically, Shu Han was not in a bad position.  The country had long been part of the Chinese wheat lands, and had a fairly large Chinese peasant population in the well irrigated plain of Ch’engtu.  There was also a wealthy merchant class, supplying grain to the surrounding mountain peoples and buying medicaments and other profitable Tibetan products.  And there were trade routes from here through the present province of Yuennan to India.