Cai Lun

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Cai Lun
Posthumous print of Cai Lun as the patron of papermaking[a]
Bornc. 50 CE
Died121 CE
Luoyang, Henan Province, China
Cai Lun
Simplified Chinese蔡伦
Traditional Chinese蔡倫

Cai Lun (Chinese: 蔡伦; c. 50 – 121 CE) or Ts'ai Lun, courtesy name Jingzhong (敬仲), was a Chinese inventor and court official of the Han dynasty. He is traditionally regarded as the inventor of paper and the papermaking process, in forms recognizable in modern times as paper. Although early forms of paper had existed in China since the 2nd century BCE, he was responsible for significant improvements and standardization of papermaking by adding essential new materials into its composition.

Cai Lun was born in Leiyang, Guiyang County (modern day Hunan), into a poor family and came to the imperial court as eunuch by at least 75 CE under Emperor Ming. Emperor Ming died the same year and was succeeded by Emperor Zhang, whose reign saw various power struggles between imperial consorts. Cai Lun's early positions involved much contact with the consorts and powerful politicians, something that would prove consequential later in his life. In 88 CE 9–10 year old Emperor He ascended to the throne due to influence of Empress Dou, who then acted as Dowager, other members of the Dou family and statesman like Cai Lun, who was promoted to the emperor's private political counselor. Dowager Empress Dou's power was short lived as a in 92 CE coup, supported by Cai Lun, removed her and her family from power. For his service, Emperor He promoted Cai Lun to the head of Imperial Supply Department, offering him the perfect opportunity to experiment for new weapons and materials, including paper.

In 105 CE Cai Lun perfected the paper making process with the use of tree bark, hemp waste, old rags, and fishnets. This greatly impressed him and spread Cai Lun's fame throughout the empire. Emperor He died that same year and was eventually succeeded by 13 year old Emperor An, whose mother, Empress Deng Sui acted as dowager and was a close acquaintance of Cai Lun. Cai Lun's invention, service and association with Dowager Empress Deng Sui eventually led to him being granted the title of Marquis and the lord of a small village in 114 CE. However, Dowager Empress Deng Sui died in 121 CE leaving Emperor An in power. The same year, a false rumor about Cai Lun's intentions to harm the emperor as well as Emperor An wanting revenge for Cai Lun's assistance in his grandmother's death led to his imprisonment, which he avoided by committing suicide. Cai was later revered in Chinese ancestor worship. Fei Zhu of the later Song Dynasty (960–1279) wrote that a temple in honor of Cai Lun had been erected in Chengdu.

Life and career[edit]

Early life[edit]

Kuiyang, [ancient Guiyang County] in present Hunan, had a culture very different from that of the midlands. In the prefecture of Kuei-Yung people lived humbly; the people were poor but lived together peacefully

Fan Ye, Volume 78 from Book of the Later Han[3]

Cai Lun was born in c. 50 CE Leiyang, of the ancient Guiyang County, (modern day Hunan province) during the Han Dynasty.[4][5] Accounts of Cai Lun's birthplace are often conflicting, likely due to the ancient Guiyang County sharing a name with the different modern day Guiyang County and the city of Guiyang.[3][6] While Leiyang city's name remains unchanged from the Han Dynasty, the ancient Guiyang county is now the prefecture-level city of Chenzhou in the Hunan province.[6][7] However, it is worth noting that modern day Leiyang is now under the jurisdiction of the city of Hengyang rather than Chenzhou.[5] Cai Lun's birth year is unknown, although it has been estimated to be c. 50 CE, with some estimates specifying 57 CE or 62 CE.[3][8][9] Almost nothing is known about his early life except that he was born into a poor family.[3] Legends suggest that near his home was a pool, south of which was a stone mortar that Cai Lun would use for papermaking.[10]

Imperial court service[edit]

Emperor Zhang, whom Cai Lun served under for 13 years.

It is not known how Cai Lun came to be in the service of the imperial court in the 70s CE. Leiyang had recently attracted government attention from its newly discovered surplus of iron, copper and zinc.[11] Ancient sources report that an iron foundry was founded to harvest the iron and transported it to the central government in Luoyang.[12] Former director of The Paper Museum in Tokyo, Kiyofusa Narita, suggests that Cai Lun may have traveled to the capital city by funds from the Iron foundry.[11] Narita cites Cai Lun's future court appointment to oversee the production of weapons, especially swords, as evidence that he must have learned the skills to do so earlier in his life, likely from the iron foundry.[11][13]

However his appointment came about, Cai Lun was known to have been castrated as a court eunuch by at least 75 CE,[b] under Emperor Ming.[14][15] Cai Lun's position was probably as a liaison between the privy council and the emperor, a position that likely involved duties akin to a chamberlain for the royal family.[11] Narita notes that this role would mean that Cai Lun would have had many chances to become acquainted with some of the most powerful men in China.[11] 75 CE also saw the death of Emperor Ming, who whose successor, Emperor Zhang, appointed Cai Lun to an Gentleman at the Yellow Gates (黃門侍郎) around 80 CE.[16][c] The climate in the court was increasingly unstable since Liu Qing, Emperor Zhang’s son from his concubine Consort Song, was the designated heir.[16] This enraged Empress Dou, Emperor Zhang’s favorite concubine, since she desired her adopted son, Prince Zhao, to be the heir. Empress Dou, her mother Princess Piyang, and her brothers planned to destroy Consort Song and her sister, another imperial consort, in order to have her adopted son crowned prince.[17] In 82 CE, Consort Song became ill and asked for herbs, so Empress Dou took the opportunity and falsely accused Consort Song of planning to use the herbs as some sort of witchcraft to harm Emperor Zhang.[17][18] Empress Dou then convinced Cai Lun to interrogate Consort Song and her sister, to force a confession; they both killed themselves.[16][19] Believing Empress Dou's accusation, Emperor Zhang removed Liu Qing as heir and appointed Prince Zhao.[17]

In 88 CE Emperor Zhang died and was succeeded by Prince Zhao, who was now Emperor He.[11] Since Emperor He was 9–10 years old, Empress Dou took control as an Empress dowager and secured her family's authority by giving various positions to her brothers Dou Xian, Dou Du, Dou Jing, and Dou Gui.[11][20] During this time Cai Lun was promoted to his most important position yet, a private counsellor to Emperor He in political matters.[21] Ancient historian, Fan Ye, suggested that this promotion was due to Cai Lun's talent and ingenuity, although Fan Yeh also mentioned that while Cai Lun was praised by Emperor He, he was criticized just as much.[13][15] In 89 CE, he may have also became the chief eunuch.[9][d] In 92 CE Emperor He had come of age and aimed to regain his power from Dowager Empress Duo, perhaps from the encouragement of Liu Qing, whose mother, Consort Song, had died as a result of the Dowager Empress Duo's rise to power.[25] Emperor He was assisted by various officials, Cai Lun and other eunuchs like Zheng Zhong among them, in the overthrowing of the Duo family.[21][25] The result of the coup was in the favor of Emperor He and he forced the 4 Dou brothers to commit suicide and exiled Dowager Empress Duo and the rest of her family to Vietnam.[25] In 97 CE, Cai Lun became well associated with Consort Deng Sui and was promoted to Shang Fang Si, making him the manager of the Imperial Supply department.[13][14][21][e] This was a very powerful role that would have included a wide variety of tasks, including the overseeing of the imperial library, the production of weapons, furniture and various other materials that would end up offering him the perfect resources to experiment and develop a more practical and higher quality version of paper.[21][26]

Standardization of paper[edit]

Five seminal steps in ancient Chinese papermaking outlined in a woodcut.

In 105 CE, Cai Lun publicly declared that he had invented a new composition for paper and papermaking process.[26] Writing had a long history in China with substitutes for paper originally being wood for short text and bamboo for lengthy text.[27][28] These alternatives were inconvenient for many reasons, being especially awkward to store, heavy and difficult to write on.[27] With the introduction of a writing hair brush by Meng Tian in the third century BCE, silk and cloth became a alternatives that addressed the problems of the current options but unfortunately their expense for production prevented widespread use.[27] The lack of a practical solution caused the continuation in experimentation of different materials and Cai Lun's solution became the most widely used in 105 CE.[29] Cai Lun's process still involved the use of bamboo but also hemp waste, old rags, fishnets and most importantly, bark from trees, probably mulberry ones.[5][30] These materials were boiled in a pulp that was beaten with a mallet, either wood or stone, and then mixed with a large amount of water. Then an unknown ingredient to bond the fiber together was added and the excess water was removed, leaving the paper finished after being dried.[8][31]

Modern investigation has proven that somewhat modern forms of paper did exist at least 3 centuries before 105 CE,[26][32] so the process to Cai Lun's proclamation was a gradual one, rather than a sudden discovery.[33] However, as sinologist Joseph Needham notes, this does not necessarily refute the credit given to Cai Lun.[34] Cai Lun did in fact perfect the papermaking form to a standard that has little changed in modern times and is recognized at the very least as the patron of its creation.[8] It has been suggested that if he was just the patron, Cai Lun took credit from someone else like how Feng Dao may have done with printing; although there is no decisive evidence to support this.[8] Many legends exist as to Cai Lun's invention, with one of the most popular ones being that Cai Lun was inspired by watching paper wasps make their nests.[35] Needham suggests that Cai Lun was inspired by the people of his birthplace, Leiyang, who used bark from the many mulberry trees to create cloth as an earlier alternative for paper.[4] Differently, Narita cites a story about how Emperor He had ordered Cai Lun to sort and organize the wooden–board books of the imperial library, a task that was probably extremely difficult due to the awkwardness and heaviness of the books.[36] Narita suggests that this task may have convinced Cai Lun that a new writing surface was needed and thus encouraged him to begin experimenting.[37] Irrespective of how of its origin, in 105 CE Cai Lun's new paper making process not only impressed Emperor He but gained him fame throughout the empire.[5][13][38]

Final years and death[edit]

Emperor He died later that year and was succeeded by the infant Emperor Shang who died before the age of 1 in 106 CE and was immediately succeeded by the 13 year old Emperor An.[31] Emperor An's young age caused Consort Deng Sui to become Dowager Empress Deng Sui and rule the empire with other officials until Emperor An came of age.[16][31] In 114 CE The Imperial Supply Department was diminished in status and power after Dowager Empress Deng Sui discovered that a lot of its profits were given to specific families rather than the government.[31] However, Cai Lun's early association with the Dowager Empress Deng Sui proved useful as while he was dismissed from his position, his loyalty and service awarded him the title of Marquis, and the lord of Lung T'ing, a small village of 300 families in the Shensi province.[5][39] Later in the year Cai Lun succeeded Zheng Zhong as a chief of the palace after his death.[16] In 117 CE, Dowager Empress Deng Sui also appointed him to oversee more than 100 scholars' in their creation of a definitive edition of the so called Five Classics.[40][5]

In CE 121, Emperor An assumed power after Empress Deng's death.[39] There were many people in the kingdom who despised the deceased Dowager Empress Deng Sui and her allies and spread a false rumour that there was a coup being planned to overthrow Emperor An, of which Cai Lun was indicated to be involved in.[5][39] Sinologist Rafe de Crespigny notes that Cai Lun's innocence was not helped by the fact that Emperor An was the grandson of Consort Song, who death was in part because of Cai Lun.[16] Cai Lun was reported to prison to answer the charges, but since he was likely to be killed he first went to his house to prepare for his death.[39] Ever since the death of his ally Empress Deng Sui, Cai Lun had carried a poison that he had made when he was the chief of the Imperial Supply Department, its use had finally come.[41] Cai Lun, ashamed that the Emperor would send him to death in such a dishonorable way, bathed, dressed in formal clothes and committed suicide by drinking the poison.[16][38] Cai Lun's death date and place are unknown, but various monuments and shrines have been erected to honor him.[42]


The creator of this extremely important invention is only somewhat known outside East Asia. After Cai invented the papermaking process in 105, it became widely used as a writing medium in China by the 3rd century.[43] It enabled China to develop its civilization (through widespread literature and literacy) much faster than it had with earlier writing materials (primarily bamboo and silk, the latter of which was a more expensive medium).

By the 600s, China's papermaking technique had spread to Korea, Vietnam, and Japan. In CE 751, some Chinese papermakers were captured by Arabs after Tang troops were defeated in the Battle of Talas River. The techniques of papermaking then spread to the West. When paper was first introduced to Europe in the 12th century, it gradually revolutionized the manner in which written communication could be spread from region to region. Along with contact between Arabs and Europeans during the Crusades (with the essential recovery of ancient Greek written classics), the widespread use of paper aided the foundation of the Scholastic Age in Europe.

See also[edit]


  1. ^ This is an 18th-century Qing dynasty print of Cai Lun with 4 attendants and a sacrificial pig and chicken; no contemporary portraits of Cai Lun survive.[1][2]
  2. ^ It is possible that Cai Lun was employed earlier than 75 CE, but record indicates that he was employed by at least 75 CE.[14]
  3. ^ This appointment would have meant that Cai Lun was attending the imperial consorts, a role that only eunuchs were eligible for.
  4. ^ While Brittanica records this, biographies by Fan Ye, Kiyofusa Narita and Joseph Needham do not mention it.[9][22][23][24]
  5. ^ Some sources claim that Cai Lun gained this position earlier, in 89 AD. This is unlikely as Narita notes that the promotion was likely a reward from Emperor He, after assisting in his successful coup.[14][21]


  1. ^ Hunter 1978, p. 51.
  2. ^ Needham 1985, pp. 108–109.
  3. ^ a b c d Narita 1954, pp. 1–2.
  4. ^ a b Needham 1985, p. 4.
  5. ^ a b c d e f g Hunter 1978, p. 52.
  6. ^ a b Official website of Leiyang Government 2019.
  7. ^ Narita 1954, p. 1.
  8. ^ a b c d Day & McNeil 1996, p. 122.
  9. ^ a b c Cai Lun | Biography, Paper & Facts | Britannica 2020.
  10. ^ Needham 1985, p. 107.
  11. ^ a b c d e f g Narita 1954, p. 2.
  12. ^ Mu-chou 2018, p. 98.
  13. ^ a b c d Carter 1925, p. 3.
  14. ^ a b c d Needham 1985, p. 40.
  15. ^ a b Hunter 1978, p. 50.
  16. ^ a b c d e f g Crespigny 2006, p. 27.
  17. ^ a b c Tan 2014, p. 107.
  18. ^ Peterson 2016, pp. 104–105.
  19. ^ Peterson 2016, p. 105.
  20. ^ Tan 2014, p. 108.
  21. ^ a b c d e Narita 1954, p. 3.
  22. ^ Carter 1925.
  23. ^ Narita 1954.
  24. ^ Needham 1985.
  25. ^ a b c Tan 2014, p. 109.
  26. ^ a b c Elliot & Rose 2009, p. 99.
  27. ^ a b c Hunter 1978, p. 48.
  28. ^ Carter 1925, p. 1.
  29. ^ Carter 1925, p. 2.
  30. ^ Needham 1985, p. 40, 57.
  31. ^ a b c d Narita 1954, p. 11.
  32. ^ Needham 1985, p. 38.
  33. ^ Narita 1954, pp. 5–8.
  34. ^ Needham 1985, p. 41.
  35. ^ Holdstock 2018, p. 101.
  36. ^ Narita 1954, p. 10.
  37. ^ Narita 1954, pp. 10–11.
  38. ^ a b Hart 2000, p. 37.
  39. ^ a b c d Narita 1954, p. 12.
  40. ^ Crespigny 2006, p. 127.
  41. ^ Narita 1954, p. 13.
  42. ^ Needham 1985, p. 47.
  43. ^ Needham 1985, p. 1.



  • Carter, Thomas Francis (1925). The Invention of Printing in China and Its Spread Westward. New York, New York: Columbia University Press. ISBN 978-0826018359.
  • Narita, Kiyofusa (1954). Life of Ts'ai Lung and Japanese Paper-Making. Tokyo, Japan: Dainihon Press. OCLC 8310445.


External links[edit]