Under the Hojo and the Ashikaga shoguns the holders of the great estates changed frequently according to the vicissitudes of those troublesome times, but under the Tokugawa no change took place, and there thus grew up a landed nobility of the most permanent character. Every one of these estates was a feudal kingdom, large or small, with its own usages and its own laws, based on the general principles above indicated and liable to be judged according to those principles by the shogun's government (_baku-fu_) in Yedo. A daimyo or feudal chief drew from the peasants on his estate the means of subsistence for himself and his retainers. For this purpose the produce of his estate was assessed by the shogun's officials in _koku_ (one _koku_ = 180.39 litres, worth about £1), and about one-half of the assessed amount went to the feudatory, the other half to the tillers of the soil. The richest daimyo was Mayeda of Kaga, whose fief was assessed at a little over a million _koku_, his revenue thus being about half a million sterling. Just as an empress had to be taken from one of five families designated to that distinction for all time, so a successor to the shogunate, failing direct heir, had to be selected from three families (_sanke_), namely, those of the daimyos of Owari, Kii and Mito, whose first representatives were three sons of Iyeyasu. Out of the total body of 255 daimyos existing in the year 1862, 141 were specially distinguished as _fudai_, or hereditary vassals of the Tokugawa house, and to 18 of these was strictly limited the perpetual privilege of filling all the high offices in the Yedo administration, while to 4 of them was reserved the special honour of supplying a regent (_go-tairo_) during the minority of the shogun. Moreover, a _fudai_ daimyo was of necessity appointed to the command of the fortress of Nijo in Kioto as well as of the great castles of Osaka and Fushimi, which Iyeyasu designated the keys of the country. No intermarriage might take place between members of the court nobility and the feudal houses without the consent of Yedo; no daimyo might apply direct to the emperor for an official title, or might put foot within the imperial district of Kioto without the shogun's permit, and at all entrances to the region known as the Kwanto there were established guardhouses, where every one, of whatever rank, must submit to be examined, in order to prevent the wives and children of the daimyos from secretly leaving Yedo for their own provinces. In their journeys to and from Yedo every second year the feudal chiefs had to travel by one of two great highways, the Tokaido or the Nakasendo, and as they moved with great retinues, these roads were provided with a number of inns and tea-houses equipped in a sumptuous manner, and having an abundance of female servants. A puissant daimyo's procession often numbered as many as 1000 retainers, and nothing illustrates more forcibly the wide