Empress Jingyin in the context of Empress Ma (Han dynasty)

Cai Lun (Chinese: 蔡伦; courtesy name: Jingzhong (敬仲); c. 50–62 – 121 CE), formerly romanized as Ts'ai Lun, was a Chinese eunuch court official of the Eastern Han dynasty. He occupies a pivotal place in the history of paper due to his addition of pulp via tree bark and hemp ends which resulted in the large-scale manufacture and worldwide spread of paper. Although traditionally regarded as the inventor of paper, earlier forms of paper have existed since the 3rd century BCE, so Cai's contributions are limited to innovation, rather than invention.

Born in Guiyang Commandery [zh] (in what is now Leiyang), Cai arrived at the imperial court in Luoyang by 75 CE, where he served as a chamberlain for Emperor Ming, and then as Xiao Huangmen, an imperial messenger for Emperor Zhang. To assist Lady Dou in securing her adopted son as designated heir, he interrogated Consort Song and her sister, who then killed themselves. When Emperor He ascended the throne in 88 CE, Dou awarded Cai with two positions: Zhongchang shi  [zh], a political counselor to the emperor that was the highest position for eunuchs of the time, and also as Shangfang Ling, where Cai oversaw the production of instruments and weapons at the Palace Workshop.

Liu Qing (Chinese: 劉慶; 78 – 1 February 107), formally Prince Xiao of Qinghe (清河孝王) or Emperor Xiaode (孝德皇), was a crown prince of the Han dynasty under his father Emperor Zhang who lost his position and his mother Consort Song due to palace intrigue at the hands of his father's wife Empress Dou. He, however, maintained a strong relationship with his half-brother Emperor He, and was able to avenge himself and his mother in conjunction with his brother. During his lifetime, he saw his son Liu Hu (劉祜) become emperor (as Emperor An) as successor to his nephew Emperor Shang, who died in infancy.