Another school of Ch’an (zen), the Northern school, which was originated by Shen-hsiu, a “rival” of Hui-neng, and taught gradual enlightenment (zengo), survived for only a short time.
With Hui-neng and his immediate dharma successors (hassu) began the great period of Ch’an (zen), which especially during the T’ang period but also in the beginning of the Sung period produced a large number of great masters. Among these were extraordinary masters such as Ma-tsu Tao-i, (Jap., Baso Dōitsu), Pai-chang Huai-hai (Jap., Hyakujō Ekai), Te-shan Hsuan-chien (Jap., Tokusan Senkan), Tung-shan Liang-chieh (Jap., Tōzan Ryōkai), Chao-chou T’ung-shen (Jap., Jōshū Jūshin), and Lin-chi I-hsüan (Jap., Rinzai Gigen). These masters largely shaped the training methods that be came typical of Ch’an (zen).
Source: The Encyclopedia of Eastern Philosophy and Religion: Buddhism, Hinduism, Taoism, Zen. Shambhala Publications, Inc.
Books on Northern school of Zen
External links: Shen-hsiu / Hui-neng / zengo / dharma / hassu / Ma-tsu Tao-i (Baso Dōitsu) / Pai-chang Huai-hai (Hyakujō Ekai) / Te-shan Hsuan-chien (Tokusan Senkan) / Tung-shan Liang-chieh (Tōzan Ryōkai) / Chao-chou T’ung-shen (Jōshū Jūshin) / Lin-chi I-hsüan (Rinzai Gigen)