Huangbo Xiyun (黃檗希運, दुर्लभ运 - Durlabhavāha / अभय運 - Abhayavāha; ཧོང་པོ་ཞི་ཡུན། hong po zhi yun Hongpo Zhiyün, universally revered across China, Japan, Korea, and East Asia as Duanji Chanshi - 斷際禪師, Chan Master of Severing Extremes, and in Japan as Ōbaku Kiun), acclaimed throughout East Asian Buddhist history as the towering 9th century master of the Hongzhou school of Chan Buddhism and the revered guru of Linji Yixuan (d. 866), stands as one of the purest, most uncompromising exponents of the One Mind doctrine in the Chinese Tripitaka. With his exact year of birth unrecorded in surviving historical chronicles (placed in the late 8th century) and his year of death in 850, Huangbo Xiyun was born in Fuzhou in Fujian province, China, possessing towering physical stature exceeding seven Chinese feet, a prominent pearl-like protuberance upon his forehead, and a serene, commanding presence. Recognizing the pervasive reality of anicca and dukkha in early youth, he practiced fearless renunciation, took formal refuge in the Buddha, the Dharma, and the Sangha, entered the monastic order at Mount Huangbo in his native Fujian, and received full monastic ordination in the Dharmaguptaka Vinaya Pitaka lineage while upholding strict monastic precepts and ethical conduct.
Determined to resolve the supreme matter of birth and death directly rather than rely upon conceptual scholarship, Huangbo Xiyun embarked on a pilgrimage to Hongzhou (modern Nanchang) in Jiangxi province hoping to meet the legendary Mazu Daoyi (709–788), only to learn upon arrival that Mazu Daoyi had already passed into parinirvana. Visiting Mazu Daoyi's memorial stupa at Shimen, Huangbo Xiyun met Mazu Daoyi's foremost disciple, the great Chan master Baizhang Huaihai (749–814), who famously tested Huangbo Xiyun by asking where he had come from and where he was going, triggering a decisive breakthrough of non-dual awakening during their celebrated dialogue regarding the wild fox koan and the direct transmission of mind.
Following Baizhang Huaihai's passing in 814, Huangbo Xiyun traveled across China—visiting Mount Tiantai, Luoyang, and Nanquan Puyuan—before eventually settling at Lingjiu Monastery on Mount Huangbo in Gao'an (Jiangxi province), which he named after his beloved home mountain in Fujian. During the devastating Huichang Persecution of Buddhism (841–845) under Emperor Wuzong of Tang, Huangbo Xiyun preserved the living lineage of Chan through austere, unshakeable contemplation, later accepting the invitation of the devout Tang scholar-official and future Prime Minister Pei Xiu (791–864) to teach at Longxing Monastery in Hongzhou and Kaiyuan Monastery in Wanling (Anhui province).
Literarily, Huangbo Xiyun left an immortal philosophical and contemplative legacy recorded verbatim by his devoted lay disciple Pei Xiu in two of the most revered classics of the Chinese Tripitaka: the Huangbo Shan Duanji Chanshi Chuanxin Fayao (黃檗山斷際禪師傳心法要, Essentials of the Transmission of Mind, Taisho Number 2012A) and the Wanling Lu (宛陵錄, Wanling Record, Taisho Number 2012B). Compiled from Pei Xiu's meticulous daily notes taken between 842 and 849 and verified directly by Huangbo Xiyun, these luminous texts present the pinnacle of Hongzhou Chan philosophy in crystal-clear, direct language stripped of all scholastic obscurantism.
Philosophically and contemplatively, Huangbo Xiyun proclaimed that all Buddhas and all sentient beings across the six realms are nothing other than One Mind (Yixin, 一心), beside which nothing else whatsoever exists. Demonstrating that this One Mind is without beginning or end, neither green nor yellow, neither existing nor non-existing, and boundless like empty space, Huangbo Xiyun taught that ordinary deluded beings suffer in samsara solely because they generate conceptual thoughts—grasping at external forms, seeking an external Buddha, or trying to manufacture enlightenment through gradual accumulation—whereas simply putting an immediate stop to conceptual proliferation reveals one's own innate Buddha-nature (tathagatagarbha) as already complete nirvana.
Harmonizing this radical immediacy with Nagarjuna's Madhyamaka dialectics regarding emptiness (शून्यता - śūnyatā; སྟོང་པ་ཉིད། stong pa nyid Tongpanyid) and dependent origination, Asanga's Yogacara phenomenology, and the Mahaparinirvana Sutra (Taisho Number 374 and Toh Number 119 in the Tibetan Tripitaka), Huangbo Xiyun guided practitioners through single-pointed meditation, mindfulness, and concentration to dissolve clinging to the five aggregates, anatta, emptiness of self, karma, and rebirth.
Throughout his teaching career—most famously in his stern, compassionate training of his foremost disciple Linji Yixuan, whom he struck three times with his wooden staff to shatter dualistic questioning and catalyze Linji Yixuan's awakening under Dayu—Huangbo Xiyun wielded uncompromising skillful means while anchoring monastic conduct in Shakyamuni Buddha's foundational teachings on the Four Noble Truths, the Noble Eightfold Path, generosity, merit, loving-kindness, compassion, equanimity, right view, non-attachment, and universal bodhicitta, uprooting the three poisons of greed, hatred, and delusion.
Passing into final parinirvana on Mount Huangbo in Jiangxi in 850 amidst extraordinary auspicious signs and deep veneration from Pei Xiu and the entire Chinese Sangha, Huangbo Xiyun was posthumously honored by Emperor Xuanzong of Tang with the imperial title Duanji Chanshi (Chan Master of Severing Extremes). Carried forward across China through Linji Yixuan and Muzhou Daoming, and honored in Japan as the eponymous ancestral patriarch of the Ōbaku school of Zen founded at Manpuku-ji by Ingen Ryūki in 1654, Huangbo Xiyun stands forever alongside Bodhidharma, Huineng, Mazu Daoyi, Baizhang Huaihai, and Nagarjuna as a supreme guardian of the Middle Way.