Imperial Prince Tsunesada (恒貞親王)

Imperial Prince Tsunesada (825 - October 12, 884) was a member of the Imperial Family during the early Heian period. He was the 2nd prince of Emperor Junna. His mother was Imperial Princess Seishi (Masako), a daughter of Emperor Saga. His other name was Imperial Prince Teishi. His Buddhist name was Gojaku.

He became a successor of Emperor Junna after the death of a half brother, Imperial Prince Tsuneyo. He was formally installed as Crown Prince when his cousin Emperor Ninmyo acceded the throne in 833. Although the Retired Emperor Junna and Imperial Prince Tsunesada refused to accept the position of Crown Prince many times, fearing to becoming involved in the power struggle, the Retired Emperor Saga and Emperor Ninmyo persuade them not to resign from the position of Crown Prince. After the Retired Emperor Junna died, however, the Showa Incident took place, and Imperial Prince Tsunesada was uncrowned in 842.

After the incident, he became a monk when he was 24 whose Buddhist name was Gojaku. He received the kanjo ceremony under the monk-Imperial Prince Shinnyo and became a founder of Saga Daikaku-ji Temple. It is said that he was requested to accede the throne when Emperor Yozei retired in 884 and the problem of succession arose, but he refused it.