C12 Understand

When I heard about Yehonala and Newcomb, I wanted to know which emperor was now in power. The name Newcobalt is too familiar. Emperor Qian Long's mother, Zhen Xing, was surnamed Zhen. Did I cross over to the Qianlong period? That's not right, Qian Long's father was Yong Zheng, how could Yong Zheng have a eunuch with the surname Lu? And Yehonala