The results, however, of conditions within the country were of much more importance than events abroad.  The Mongols made Peking their capital as was entirely natural, for Peking was near their homeland Mongolia.  The emperor and his entourage could return to Mongolia in the summer, when China became too hot or too humid for them; and from Peking they were able to maintain contact with the rest of the Mongol empire.  But as the city had become the capital of a vast empire, an enormous staff of officials had to be housed there, consisting of persons of many different nationalities.  The emperor naturally wanted to have a magnificent capital, a city really worthy of so vast an empire.  As the many wars had brought in vast booty, there was money for the building of great palaces, of a size and magnificence never before seen in China.  They were built by Chinese forced labour, and to this end men had to be brought from all over the empire—­poor peasants, whose fields went out of cultivation while they were held in bondage far away.  If they ever returned home, they were destitute and had lost their land.  The rich gentry, on the other hand, were able to buy immunity from forced labour.  The immense increase in the population of Peking (the huge court with its enormous expenditure, the mass of officials, the great merchant community, largely foreigners, and the many servile labourers), necessitated vast supplies of food.  Now, as mentioned in earlier chapters, since the time of the Later T’ang the region round Nanking had become the main centre of production in China, and the Chinese population had gone over more and more to the consumption of rice instead of pulse or wheat.  As rice could not be grown in the north, practically the whole of the food supplies for the capital had to be brought from the south.  The transport system taken over by the Mongols had not been created for long-distance traffic of this sort.  The capital of the Sung had lain in the main centre of production.  Consequently, a great fleet had suddenly to be built, canals and rivers had to be regulated, and some new canals excavated.  This again called for a vast quantity of forced labour, often brought from afar to the points at which it was needed.  The Chinese peasants had suffered in the Sung period.  They had been exploited by the large landowners.  The Mongols had not removed these landowners, as the Chinese gentry had gone over to their side.  The Mongols had deprived them of their political power, but had left them their estates, the basis of their power.  In past changes of dynasty the gentry had either maintained their position or been replaced by a new gentry:  the total number of their class had remained virtually unchanged.  Now, however, in addition to the original gentry there were about a million Mongols, for whose maintenance the peasants had also to provide, and their standard of maintenance was high.  This was an enormous increase in the burdens of the peasantry.