In 817 B.C. the Emperor himself is censured by history for having, "contrary to rule," wished to set up as ruler of Lu a second son in preference to the elder son; he repeated the act in 796, as has already been explained in Chapter XX., when a few other instances were cited to illustrate the general rule in China. At this time the waning power of the emperors still evidently flickered. In 608, through the meddlesome political interference of Ts'i, a concubine's son succeeded to the Lu throne in preference to the legitimate wife's son; curiously enough, the legitimate wife was a Ts'i princess. The result of this irregularity was that the "three powerful families" of Lu (themselves descendants of the ruling family) grew restless, and the state began to decline. On the death of a King of Ts'u in 516, it was proposed to put on the throne, instead of the king's young son, the king's younger brother by an inferior mother, on the ground that the mother of the young son in question was the wife obtained from Ts'in by the king for marriage to his eldest son (who had since joined the king's enemies), which young lady the king had subsequently decided to marry himself. Even under this irregular and complicated family tangle, the proposed succession was disapproved by the counsellors, on the ground that irregular successions invariably produced trouble in the state. In the year 450 B.C. the ruler of Ts'i insisted, against advice, on the succession of a younger son by a favourite concubine in preference to his elder sons by superior mothers, including the first and most dignified spouse. But here, again, the powerful families intervened; one of the elder sons, who had fled to Lu, was brought back secretly in a sack; the wrongful successor was murdered, and the "powerful family" which took the lead in state affairs soon afterwards, to the horror of Confucius, by intrigue and by further assassination, secured the Ts'i throne for itself. It will thus be noticed that all the great states except Ts'in had their full share of succession troubles.