A a fost numit co-împărat în 654, de către tatăl său împăratul [[Constans al II-lea]] şi a devenit împărat după ce Constans a fost asasinat în anul 668.
Împăratul Constantin called the al IV-lea a convocat [[Sixth Ecumenical Councilal şaselea Sinod Ecumenic]] (also known as the Third Council of Constantinoplecunoscut şi ca al treilea Sinod de la Constantinopol) that met from November of , care a durat din noiembrie 680 until September of până în septembrie 681. During its 18 sittings, 12 of which were actually led by Constantine himself, the council attempted to bring about a reconciliation between the [[Church of Rome|Western Church in Rome]] and the Orthodox Church in Constantinople. The council decreed that Christ had both a divine and human will that matched his two natures, reaffirming the doctrines of the [[Fourth Ecumenical Council|Council of Chalcedon]] in 451. This solved the controversy over [[monothelitism]]. The council's actions helped to promote a feeling of unity between the two churches and bring them closer together than they had been in recent years.
He was buried at the [[Church of the Holy Apostles (Constantinople)|Church of the Holy Apostles]] in Constantinople.
