The name by which we know the emperor of China was not his personal or family name, but was assumed on ascending the throne, and in old times was frequently changed. But from the time of the Sung dynasty such a change has only once occurred. This was in the case of the unfortunate Ming emperor Cheng-tung, to whom we referred on p. 93. We rarely find the name of any emperor of an earlier time than the Ming dynasty on porcelain, and the few instances that do occur are obvious forgeries. Perhaps the earliest date on Chinese porcelain with any claim to authority is the _nien-hao_ of Yung-lo (1402-25), in quaint ‘tadpole’ characters engraved in the paste beneath the glaze. This inscription occurs on the thin bowl of Ting ware in the British Museum, described on page 67 (PL. A. 1). We have said before, and we cannot too strongly impress this fact upon the reader, that the vast majority of the Ming marks so frequently found on Chinese porcelain are of no value. They teach us nothing themselves, and when we can accept them it is on evidence derived from other sources. As Franks observed many years ago, all we can say is that a piece of porcelain is not older than the date which it bears. When we find the date inscribed in a horizontal line round the neck of a vase, as is not infrequent in later Ming times, especially in the reign of Wan-li[74] (1572-1619), more reliance may perhaps be put on it, as regards ware of Chinese origin at least, for the Japanese were very fond of decorating their blue and white ware with Ming inscriptions placed in this position. We have innumerable vases in our collections undoubtedly made in the reign of the great Kang-he (1661-1722),[75] but his reign-mark is comparatively rarely found. The absence of this _nien-hao_ is usually explained by a proclamation, issued in 1677, which has been preserved in the Chinese books, forbidding the inscription of the imperial name on porcelain. With this proclamation the empty double ring of blue often found on the base of vases of this time may perhaps be connected. Many of the finest pieces, however, bear no mark of any kind.