He served as Co-emperor of the Byzantine Empire with his father Justinian II, from 706–711 AD. He was killed in 711 AD, when Bardanes led a rebellion, which marched on Constantinople, killing Justinian as well as Tiberius. After his death, two different individuals impersonated him, with one, named Bashir, going on to be hosted by Hisham ibn Abd al-Malik, the Umayyad Caliph, before his lie was discovered and he was crucified.