Tessō Keishū
Tessō Keishū (鉄叟 景秀; 1496–1580) was a monk of the Sengoku–Shokuho period.[1]

Born in 1496, he belonged to the Rinzai sect of Zen Buddhism.[1] He succeeded to the Dharma of Reichū Zen'ei of Eigen-ji in Ōmi.[1] He served as abbot of Kennin-ji and Nanzen-ji in Kyoto,[1] the top of Rinzai Zen establishment known collectively as the Five Mountains (Gosan).[2] At one point he resided at Shōmyō-ji in Hino.[2] In 1579, at the age of 84 and already deaf, he was appointed chief judge by Oda Nobunaga. He also served as judge at the Azuchi religious debate,[1] later confessing to Nobunaga that he had not even heard it.[3] He died on the 18th day of the 11th month of 1580, at the age of 85.[1]