Two imperial edicts written on silk scrolls during the Ming Dynasty more than 500 years ago have been discovered in northern China's Hebei Province.

The imperial edicts, order or comment from emperors, are a family heirloom belonging to 80-year-old Cui Xibo, who showed them to researchers and archaeologists yesterday as local authorities conducted an archaeological survey in Guangzong County.

One of the edicts, issued in the 11th year of Emperor Chenghua's reign, is 3.42 metres long and 33 centimetres wide and has 412 words, in which the emperor praised Cui's ancestor Cui Gong, the personnel minister at that time, for his hard work and diligence, state-run Xinhua agency reported.

The second, issued in the 22nd year of Emperor Jiajing's reign, is four metres long and 33 centimetres wide.

In the 374 words of text, Cui Yue, grandson of Cui Gong and also an official, was promoted by the emperor.

"The two imperial edicts share similar design and texture, and they will help us research how officials were appointed and promoted in the Ming Dynasty," said historian Gu Huachi.

The family treasures were handed down to the first son in each generation of Cui's family.

"I'll keep handing them down. They record the great achievements of our ancestors and can encourage our offspring," Cui Xibo said.

The Ming dynasty was the ruling dynasty of China for 276 years (1368-1644) following the collapse of the Mongol-led Yuan dynasty.

The Ming, described by some as "one of the greatest eras of orderly government and social stability in human history, was the last dynasty in China ruled by ethnic Han Chinese.