Saint Vitalian played a crucial role in fostering unity between Rome and Constantinople, working toward reconciliation with Emperor Constans II and the Eastern Church. He also strengthened the Church in Britain, supported liturgical reforms, and promoted sacred music in the Lateran Basilica.

Pope Vitalian was elected as the successor of Pope Eugene I and the seventy-sixth Pope of the Holy Church on July 30, AD657, at a time when the problems raised by the heresy of Monothelitism remained unresolved.

Following in the footsteps of his predecessor, Pope Eugene, Pope Vitalian endeavored to act as a peacemaker by fostering renewed ties with Constantinople through diplomatic efforts with Eastern Emperor Constans II, all while seeking a resolution to the ongoing Monothelite controversy. In recognition of his papacy, the emperor formally affirmed his position as the head of the Church and presented him with an exquisite codex of the Gospels, adorned with rare gems and encased in golden trappings. At the same time, Peter, Patriarch of Constantinople, added the name of Pope Vitalian along with other names to be prayed for at the Holy Mass. After Pope Honorius I, Pope Vitalian was the first pope to be so prayed for.

In AD 663, Emperor Constans made an official visit to Rome, where the Roman Church and clergy, despite the suffering they endured from his persecution of Pope Martin I and his edict banning discussions on Christ’s nature and will, received him with great pomp and ceremony. However, the emperor took several actions that went against the pope’s wishes, including elevating Ravenna to an independent diocese with the authority to elect its own bishop. Additionally, he decreed that any bishop elected in Ravenna would require royal approval for their appointment to be considered valid.

After the assassination of Emperor Constans II, his son, Constantine IV, ascended the throne with the support of Pope Vitalian, who endorsed him as the new emperor of the Roman Empire. In gratitude, Emperor Constantine IV rescinded his father's royal proclamation, the Typos, and granted the pope full authority to teach the Church’s official doctrine, affirming that Christ possessed both divine and human natures, as well as divine and human wills. When Patriarch John IV issued documents deemed unorthodox, the emperor rejected them. In response, Patriarch Theodore attempted to remove the pope’s name from the Mass, but Constantine IV intervened and prevented the action.

Pope Vitalian played a crucial role in strengthening church relations with England, particularly during the Synod of Whitby, where Northumbrian overlord King Oswy, in consultation with the Patriarch, accepted the Easter dates observed by the pope. To further support the king’s education, Pope Vitalian appointed the highly intelligent and scholarly Theodore of Tarsus as his tutor in both Latin and Greek.

Meanwhile, when Archbishop Marius of the See of Ravenna declared independence from papal authority under the patronage of the Eastern Emperors, Constans II reinforced this separation by issuing an edict that removed Ravenna from the ecclesiastical jurisdiction of Rome.

Pope Vitalian established a music school in the Lateran Basilica to foster Byzantine music and to train Church music ministers.

Pope Vitalian, who courageously led the Church and paved the way for unity in the Church, passed away on January 27, AD672. His mortal remains were to rest in St. Peter's Basilica.