When the family fortune of the Sugawara clan declined after the Shotai Incident (901), the Oe clan conversely began to occupy the post of Monjo hakase so that the clan increased its influence on the Monjoin.
昌泰の変後に菅原氏が一時低迷すると、替わって大江氏が文章博士を占めるようになり、文章院への影響力を強めた。