In 918 Saiko was assigned to the first chori (a chief priest and a common name of Monseki or Monzeki, the head priest who was born as Imperial Family) of the Kashu-ji Temple, which led to its prosperity.
918年（延喜18年）には、勧修寺に長吏（住職・門跡の通称）を置いて済高が長吏に任じられたころから、勧修寺が隆盛を極める契機となった。