via xuefeng yicun the fayang school and yunmen school are traced back to shitou xiqian and huineng. xuefeng was one of the most influential chán-teachers at the end of the tang dynasty, when "a widely influential zen center formed around xuefeng yicun". the loss of control by the tang dynasty, and the accompanying loss of support for buddhist institutions, lead to a regionally based chan of xuefeng and his students.