The new emperor's younger brother by another mother, Prince Iyo, was accused the next year of plotting a coup, and ultimately committed suicide.
[2] Angered by Saga's attempt to change the kansatsu-shi (観察使) regional inspection system he had established, the retired emperor set up a competing court.
In the autumn of 810, amid the deepening rivalry between the two courts, Heizei issued an order to abandon Heian-kyō and move the capital back to Heijō-kyō.
This came as an unexpected move to Saga, who played along for the moment by appointing Sakanoue no Tamuramaro, Fujiwara no Fuyutsugu, and Ki no Taue (紀田上) in charge of construction there.
Meanwhile, he promoted the three officials he had appointed to manage construction: Tamuramaro to dainagon, Fuyutsugu to vice-minister of the Shikibu-shō, and Taue to governor of Owari Province.
Many of his retainers, including the chūnagon Fujiwara no Kadonomaro, warned him strongly against this, but Heizei boarded a palanquin with Kusuko and embarked.
Heizei and Kusuko made it only as far as Soekami District in Yamato Province before realizing that Emperor Saga's forces had tightened their guard.
The monk Kūkai, who had prayed for Emperor Saga's side during the incident, was also able to use this success as an opportunity to elevate himself as the leading Buddhist figure in Japan.