Huang Po, also known as Huangbo Xiyun, was a prominent Chinese Zen Buddhist master who lived during the Tang Dynasty (approximately 840-901 CE). He is best known for his teachings on the nature of enlightenment and the importance of direct experience in understanding reality. His teachings emphasize the concept of non-duality, which suggests that the distinction between self and other is an illusion. Huang Po's most famous work is the "Transmission of Mind," where he articulates his views on the nature of the mind and the path to awakening. He was a significant figure in the development of Zen Buddhism in China and influenced many later Zen masters, including Linji Yixuan, who founded the Linji school of Zen.