Cai Lun (; courtesy name: Jingzhong (); – 121 CE), formerly romanized as Ts'ai Lun, was a Chinese eunuch court official of the Eastern Han dynasty. He is traditionally regarded as the inventor of paper and the modern papermaking process, as he originated paper in its modern form. Although early forms of paper had existed since at least the 3rd century BCE, he occupies a pivotal place in the history of paper due to his addition of important new materials, such as tree bark and hemp ends, which resulted in the large-scale manufacture and rapid spread of paper.