By the time of the Song Dynasty, Muslims had come to play a major role in the import/export industry.

The use of silver as money was very established at the time of the Ming Dynasty (1368-1644).

By the time of the 19th Dynasty their employees enjoyed such benefits as medical insurance, pensions and sick leave.

Go was originally played on a 17x17 line grid, but a 19x19 grid became standard by the time of the Tang Dynasty (618-907).

From the time of the Shang Dynasty (1700 BC), some written history is available.

By the time of the Tang Dynasty (618-907), the aesthetic and structural objectives for hanging scrolls were summarized, which are still followed to this day.

The work contained 100 volumes at the time that it was written, but some volumes were already missing by the time of the Song Dynasty.

"That would put it at the time of either the second Ho-nethite Dynasty or the second Vorduvian," the scholar said.

That atomic power was known by the time of the Fifth Dynasty is a fact of which we are certain.

By the time of the Ming Dynasty (1368-1644) two types of huochong were in use.