Cai Lun
Palace intrigue and workshop
### Palace intrigue and workshop

Since 82 CE, [Liu Qing](/wiki/Liu_Qing_%28prince%29 "Liu Qing (prince)"), Zhang's son from his concubine [Consort Song](/wiki/Empress_Jingyin "Empress Jingyin"), had been the [designated heir](/wiki/Taizi "Taizi"), secured by the favor of [Empress Ma](/wiki/Empress_Ma_%28Han_dynasty%29 "Empress Ma (Han dynasty)"). However, Ma's death in 79 CE made [Lady Dou](/wiki/Empress_Dou_%28Zhang%29 "Empress Dou (Zhang)") the empress, and—aiming to develop her family's power—she adopted [Prince Zhao](/wiki/Emperor_He_of_Han "Emperor He of Han") with the intention of installing him as heir. As a result, when Song became ill in 82 and asked for herbs, Dou falsely accused her of planning to use the herbs for witchcraft against Zhang. Dou then ordered Cai to interrogate Consort Song and her sister, another imperial consort, to force a confession; they both killed themselves. Believing Dou's accusation, Zhang replaced Liu Qing with Prince Zhao as heir.

Prince Zhao, ruling as Emperor He, was 10 years old at his accession in 88 CE, so Dou took control as [empress dowager](/wiki/Empress_dowager "Empress dowager") and secured her authority by giving various positions to her four brothers, particularly [Dou Xian](/wiki/Dou_Xian "Dou Xian"), who promoted Cai to  (; "Regular Attendant") for his loyalty. Cai served as a private counselor to He in political matters;:""  
"After Emperor He took the throne, he became , and he participated in key strategic decisions."  
: "The Emperor He, on coming to the throne, knowing that Cai Lun was a man full of talent and zeal, appointed him a privy counsellor."  
: "The Emperor He, upon his accession, learning of Cai Lun's superior qualities and talents, named him private counsellor". this post gave Cai a salary\-rank of 2000 *shi*, and was the highest eunuch\-exclusive position, which also made him a chief eunuch of the palace. In the , Cai was characterized as, in the words of de Crespigny, "honest, cautious and a good judge of policy".:""  
"Cai Lun was talented and learned. He used his full effort and was careful. He often was willing to correct the wrongs, even when it offended the stern faced \[those in power]. When he had vacation days, he would close his door and not entertain guests, but spent time in the field." Cai was also designated  (; "Prefect of the Palace Workshop" or "Prefect of the Masters of Techniques") later in 88 or 89 CE.:""  
"He was later given the additional post of Shangfangling." While in this eunuch\-only position, he would have been responsible for the production of instruments and weapons for imperial use. The role had a salary\-rank of 600 *shi*—though this was in addition to the 2000 *shi* from his continued  post.

When Emperor He came of age in 92 CE he led various officials, especially [Zheng Zhong](/wiki/Zheng_Zhong "Zheng Zhong"), in a [coup d'état](/wiki/Coup_d%27%C3%A9tat "Coup d'état") to overthrow the Dou family. Cai was not involved in their removal, and though he was previously allied with the family, he was undisturbed by the Emperor's coup. In 97 CE, his position as  expanded in scope, as he became responsible for [ceremonial swords](/wiki/Ceremonial_weapon "Ceremonial weapon") and other items. The  describes his craftsmanship as high\-quality and a model for later generations.:""  
"In the 9th year of the  era \[97], he oversaw the manufacturing of imperial swords and other equipment, which were all made carefully and well, and he became an example for later generations."  
: "In the ninth year of the period  (97\) Cai Lun became inspector of public works. By his plans and according to his arrangements, engineers and workmen made, always with the best of materials, swords and arms of various sorts. Later generations could do no better than imitate his methods of work."  
: "In the ninth year of the reign of  (97\), Cai Lun was made inspector of works and through his efforts the engineers and workmen by the use of fine materials and skill produced swords and arms that served as models for future generations."


How old was Emperor He when he took the throne?