The adoption of Buddhism meant to the Japanese much more than the acquisition of a practical religion with a code of clearly defined morality in place of the amorphous and jejune cult of Shinto. It meant the introduction of Chinese civilization. Priests and scholars crossed in numbers from China, and men passed over from Japan to study the Sutras at what was then regarded as the fountain-head of Buddhism. There was also a constant stream of immigrants from China and Korea, and the result may be gathered from the fact that a census taken of the Japanese nobility in 814 indicated 382 Korean and Chinese families against only 796 of pure Japanese origin. The records show that in costume and customs a signal advance was made towards refinement. Hair-ornaments of gold or silver chiselled in the form of flowers; caps of sarcenet in twelve special tints, each indicating a different grade; garments of brocade and embroidery with figured thin silks of various colours--all these were worn on ceremonial occasions; the art of painting was introduced; a recorder's office was established; perfumes were largely employed; court picnics to gather medicinal herbs were instituted, princes and princesses attending in brilliant raiment; Chinese music and dancing were introduced; cross bows and catapults were added to the weapons of war; domestic architecture made signal strides in obedience to the examples of Buddhist sacred edifices, which, from the first, showed magnificence of dimension and decoration hitherto unconceived in Japan; the arts of metal-casting and sculpture underwent great improvement; Prince Shotoku compiled a code, commonly spoken of as the first written laws of Japan, but in reality a collection of maxims evincing a moral spirit of the highest type. In some respects, however, there was no improvement. The succession to the throne still tended to provoke disputes among the Imperial princes; the sword constituted the principal weapon of punishment, and torture the chief judicial device. Now, too, for the first time, a noble family is found seeking to usurp the Imperial authority. The head of the Soga house, Umako, having compassed the murder of the emperor Sujun and placed on the throne his own niece (Suiko), swept away all opposition to the latter's successor, Jomei, and controlled the administration of state affairs throughout two reigns. In all this he was strongly seconded by his son, Iruka, who even surpassed him in contumelious assumption of power and parade of dignity. Iruka was slain in the presence of the empress Kogyoku by Prince Naka with the assistance of the minister of the interior, Kamako, and it is not surprising to find the empress (Kogyoku) abdicating immediately afterwards in favour of Kamako's protégé, Prince Karu, who is known in history as Kotoku. This Kamako, planner and leader of the conspiracy which overthrew the Soga, is remembered by posterity under the name of