Cai Lun

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 is an important figure in the history of paper. He added pulp made from tree bark and hemp ends, which helped paper be made on a large scale and spread around the world. Cai is often called the inventor of paper, but earlier forms of paper existed from the 3rd century BCE. His work was an innovation rather than an invention.

Cai was born in Guiyang Commandery, in what is now Leiyang. By 75 CE, he had arrived at the imperial court in Luoyang. He served as a chamberlain for Emperor Ming and later as Xiao Huangmen, an imperial messenger for Emperor Zhang. He helped Lady Dou try to make her adopted son the designated heir. In this work, he questioned Consort Song and her sister. When Emperor He became emperor in 88 CE, Dou gave Cai two positions. One was political counselor to the emperor, the highest position for eunuchs at that time. The other was Shangfang Ling, where Cai oversaw the making of instruments and weapons at the Palace Workshop.

In 92 CE, Emperor He carried out a successful coup d'état against the Dou family. Cai was not harmed by the fall of his former ally. His work at the Palace Workshop grew, and he became responsible for making ceremonial weapons. The Hou Hanshu says these weapons were very well made. Cai's most famous work came in 105 CE. He greatly improved papermaking by using tree bark, hemp waste, old rags, and fishnets. His new paper quickly took the place of the bamboo and wooden slips that had been used until then. Cai became wealthy and famous across the empire.

In 110 CE, Lady Deng, who had become the empress dowager to the young Emperor An, chose Cai to lead 100 scholars preparing a new edition of the Five Classics. In 114 CE, Cai was rewarded for his service to the emperor. He received the title of marquis and was enfeoffed as lord of Longting, a small village. When his ally Deng died in 121 CE, Cai was moved to the Ministry of Justice. This happened because of his part in the death of the emperor's grandmother, Consort Song.

Cai's improvements to papermaking are believed to have had a huge effect on human history. Of the people who created China's Four Great Inventions, which are the compass, gunpowder, papermaking, and printing, Cai is the only early figure whose name is known. In China he is honored in ancestor worship, deified as the god of papermaking, and appears in Chinese folklore. Outside of East Asia, however, he is mostly unknown. His hometown of Leiyang is still an active center of paper production.