Nikephoros I, on becoming emperor after Irene…

Nikephoros I, on becoming emperor after Irene was deposed, had refused to pay tribute to Harun, saying that Irene should have been receiving the tribute the whole time.

News of this angers Harun, who writes a message on the back of the Roman emperor's letter and says,

"In the name of God the most merciful, From Amir al-Mu'minin Harun al-Rashid, commander of the faithful, to Nikephoros, dog of the Romans.

Thou shalt not hear, thou shalt behold my reply".