KEIZAN (1264–1325), more fully Keizan Jōkin, was the founding abbot of the Sōjiji Zen monastery. Since the late nineteenth century, he has officially been designated, along with Dōgen (1200–1253), as one of the two founding patriarchs of the Japanese Sōtō Zen school.

Born in 1264 (not 1268 as previously assumed), Keizan entered Eiheiji, the Zen monastery founded by Dōgen in Echizen province, in 1276. Keizan studied Zen directly under four of Dōgen's leading disciples: Ejō (1198–1280), Jakuen (1207–1299), Gien (d. 1313), and Gikai (1219–1309). In 1298 Keizan succeeded Gikai as second abbot of Daijōji monastery in Kaga province. Eventually Keizan entrusted Daijōji to his disciple, Meihō Sotetsu (1277–1350), and began constructing a new monastery in Noto province named Tōkoku-san Yōkōji, which he envisioned as the future headquarters of the Sōtō Zen lineage in Japan. With Yōkōji as his base, Keizan founded six more monasteries nearby...