Yung-lo’s successor died early.  Under the latter’s son, the emperor Hsuean Tsung (1426-1435; reign name Hsuean-te), fixed numbers of candidates were assigned for the state examinations.  It had been found that almost the whole of the gentry in the Yangtze region sat at the examinations; and that at these examinations their representatives made sure, through their mutual relations, that only their members should pass, so that the candidates from the north were virtually excluded.  The important military clique in the north protested against this, and a compromise was arrived at:  at every examination one-third of the candidates must come from the north and two-thirds from the south.  This system lasted for a long time, and led to many disputes.

At his death Hsuean Tsung left the empire to his eight-year-old son Ying Tsung (1436-49 and 1459-64), who was entirely in the hands of the Yang clique, which was associated with his grandmother.  Soon, however, another clique, led by the eunuch Wang Chen, gained the upper hand at court.  The Mongols were very active at this time, and made several raids on the province of Shansi; Wang Chen proposed a great campaign against them, and in this campaign he took with him the young emperor, who had reached his twenty-first birthday in 1449.  The emperor had grown up in the palace and knew nothing of the world outside; he was therefore glad to go with Wang Chen; but that eunuch had also lived in the palace and also knew nothing of the world, and in particular of war.  Consequently he failed in the organization of reinforcements for his army, some 100,000 strong; after a few brief engagements the Oirat-Mongol prince Esen had the imperial army surrounded and the emperor a prisoner.  The eunuch Wang Chen came to his end, and his clique, of course, no longer counted.  The Mongols had no intention of killing the emperor; they proposed to hold him to ransom, at a high price.  The various cliques at court cared little, however, about their ruler.  After the fall of the Wang clique there were two others, of which one, that of General Yue, became particularly powerful, as he had been able to repel a Mongol attack on Peking.  Yue proclaimed a new emperor—­not the captive emperor’s son, a baby, but his brother, who became the emperor Ching Tsung.  The Yang clique insisted on the rights of the imperial baby.  From all this the Mongols saw that the Chinese were not inclined to spend a lot of money on their imperial captive.  Accordingly they made an enormous reduction in the ransom demanded, and more or less forced the Chinese to take back their former emperor.  The Mongols hoped that this would at least produce political disturbances by which they might profit, once the old emperor was back in Peking.  And this did soon happen.  At first the ransomed emperor was pushed out of sight into a palace, and Ching Tsung continued to reign.  But in 1456 Ching Tsung fell ill, and a successor to him had to be chosen.  The Yue clique wanted to have the son of Ching Tsung; the Yang clique wanted the son of the deposed emperor Ying Tsung.  No agreement was reached, so that in the end a third clique, led by the soldier Shih Heng, who had helped to defend Peking against the Mongols, found its opportunity, and by a coup d’ etat reinstated the deposed emperor Ying Tsung.