that contain the reign name of Chinese emperors or a dynasty (reign or dynastic marks) may sometimes hint to the period of production,
but this is actually quite unreliable due to the frequent use of non-period
marks, that is marks of an earlier reign or period in which an item was
A reign name was assumed when a new emperor ascended the throne. This was not his family or clan name. For example the emperors of the Ming dynasty had the family name 'Zhu', but each emperor had a different name. The first one was the Hongwu emperor, who assumed this name upon becoming emperor. Year counting started anew when an emperor ascended the throne.
It is known that some reign names of earlier Ming emperors can be found on marks of late Ming dynasty porcelain.
Even porcelain of the early Qing dynasty frequently shows reign marks bearing the name of Ming emperors. In the late Qing dynasty and republican era the reign marks of earlier Qing emperors often were added with the intention to increase the perceived value of the porcelain.
An overall judgement of the porcelain piece is always necessary to verify if its real age and the period mark fit together. Dating based on a mark alone is mostly impossible with Chinese ceramics.
In the table below the reign name is listed and the duration is shown in western years. In reality, with imperial year notation the year count started again with year 'one', each time a new emperor was enthroned.
comparing the Chinese characters used in the marks of ceramics, the
emperors' reign names for the Ming and Qing dynasties are given in
Chinese on the following page:
Chinese emperors' reign names (in Chinese)
Please note that the imperial year notation which uses the reign name of the emperor in combination with the year during which something happened, was the most common way of recording events, history, etc. in ancient China.
This was not limited to ceramics and their marks.