Yuwen Yong had been the emperor of the Northern Zhou Dynasty for 18 years.
Yuwen Yong reigned for nineteen years, from 560 AD to 578 AD when he died of illness.
Yuwen Yong had been emperor for 19 years, from 560 to 578.
Yuwen Yong had been emperor for 19 years, from 560 to 578.
Yuwen Yong had been emperor for 19 years, from 560 to 578.
Yuwen Yong had been emperor for 19 years, from 560 to 578.
Yuwen Yong had been emperor for 19 years, from 560 to 578.
Yuwen Huaji had been emperor for half a year, but there was no specific information about how many years he had been emperor.
An Lushan had been the emperor for two years. In the first month of the year 756, he claimed to be Emperor Xiongwu, with the title of Great Yan and the title of Shengwu. However, he was killed by his subordinates in the year 757.