Huangbo Xiyun was a prominent Chinese Zen Buddhist master who lived during the Tang Dynasty (618-907 CE). He is best known for his teachings on direct experience and the nature of enlightenment, emphasizing the importance of personal insight over textual study. His teachings contributed significantly to the development of the Linji school of Zen Buddhism. Huangbo's most famous disciple was Linji Yixuan, who founded the Linji school and popularized the use of koans, or paradoxical anecdotes, to provoke deep thought and realization. Huangbo's influence extended beyond his lifetime, shaping the practice and philosophy of Zen Buddhism in China and later in Japan.