THE HEI-AN EPOCH. 794-1186 A. D. The Nara epoch had come to an end when in 794 the Emperor Kwammu transferred the capital to Kyōto. The new seat of government being then known as _Hei-an Kyō_, or Citadel of Tranquillity, the interval that separated its choice as capital from the establishment of feudal administration at Kamakura in 1186--an interval of nearly four centuries--is known in history as the Hei-an epoch. A few words may be said about the significance of the change of the seat of government from Nara to Kyōto. From ancient times it had been the custom for the emperor and the heir apparent to live apart, from which fact it resulted that when a sovereign died and his son succeeded to the throne, the latter usually transferred the capital to the site of his own palace. It sometimes happened also that the residence of the imperial court was altered as often as two or three times during the same reign. Rarely, however, did the court move out of the contiguous provinces known as the _Go-kinai_, the great majority of the seats of government being in the province of Yamato. So long as the government was comparatively simple, the transfer of its seat from place to place involved no serious effort. As, however, the business of administration became more complicated, and intercourse with China grew more intimate, the character of the palace assumed magnificence proportionate to the imperial ceremonies and national receptions that had to be held there. Hence the capital established at Nara by the Empress Gemmyō was on a scale of unprecedented magnitude and splendor. There seven sovereigns reigned in succession without any thought of moving elsewhere. But when the Emperor Kwammu assumed the reins of government, he found that Nara was not a convenient place for administrative purposes. He at first moved to Nagaoka in Yamashiro, but a brief residence there convinced him that his choice had not been well guided. At last, in 794, a new capital was built, after the model of Nara, with some modifications introduced from the metropolis of the T'ang dynasty in China, at Uda in the same province. This was called Kyōto, which means capital. It measured from north to south 17,530 feet and from east to west 15,080 feet, the whole being surrounded by moats and palisades, and the imperial palace being situated in the center of the northern portion. From the southern palace gate (_Shujaku-mon_) to the southernmost city gate (_Rajo-mon_) a long street, 280 feet wide (called _Shujaku-ōji_, or the main Shujaku thoroughfare), extended in one straight line, separating the city into two parts, of which the eastern was designated _Sakyō_, or the left capital, and the western, _Ukyō_, or the right capital. The whole city, from east to west, was divided into nine districts (_jo_), and between the first and second districts lay the imperial palace.