Originally the Ts'ao-Tung (jp. Soto) branch of Ch'an (jp. Zen) Buddhism in China founded by Dong Shan Liang-Chieh and Pen-Chi in the 9th century and brought to Japan by Eihei Dogen zenji in the thirteenth century. This school emphasizes the experiential practice of seated concentration called Zazen (sometimes called Silent Illumination) over ritual or academic activities. Ts'ao and Tung are the names of mountains near the monasteries where this school began.