Toto and his armed men, hearing that Pope Paul is on the verge of dying, force their way into Rome through the Gate of St. Pancratius on June 28.
With Paul’s death, Toto makes his way to the Basilica of the Apostles where the other members of the papal court and Roman nobility are gathering, and here Christophorus has everyone swear that they would all uphold each other’s rights during the upcoming election.
However, as soon as the meeting breaks up, Toto’s armed retainers assemble in his house at Rome and elect his brother Constantine as pope.
Since Constantine is still a layperson, he needs to be ordained deacon and priest and then consecrated as bishop in rapid succession.
Although frowned upon by canon law, this approach is far from unknown at this time.
Therefore, accompanied by a group of armed men, he is escorted to the Lateran Palace, where they attempt to force George, the Bishop of Praeneste, to ordain Constantine as a monk.
George throws himself at Constantine’s feet, begging Constantine not to make him do this.
However, Constantine and his supporters make it clear that he will be forced to, one way or another.
George therefore performs the ceremony, ordaining Constantine as a monk.
The next day, June 29, Bishop George makes Constantine a subdeacon followed immediately by his elevation to deacon.
This contravenes canon law, which requires an interval between the giving of the major orders of at least one day.
The Roman people are now required to take an oath of fidelity to Constantine, who again forces George of Praeneste, together with bishops Eustratius of Albano and Citonatus of Porto, to consecrate him as Bishop of Rome on July 5, 767.
In the meantime, opposition to the antipope is being led by Christophorus, the Primicerius, and his son Sergius, the treasurer of the Roman church.
Noting, however, that their lives are in danger, they flee for sanctuary to St. Peter’s Basilica, where they will remain until April 768.
One of Constantine’s first acts is to give notice to the Frankish King, Pepin the Short, of his election, to secure the king’s approval of his actions.
Constantine’s letter to Pepin declares that, against his wishes, he had been raised to the Apostolic See by "the people of Rome and the cities adjoining it", and that he hoped for the continuation of the friendship Pepin had shown to both his predecessors, Paul I and Stephen II.
Pepin ignores this letter, forcing Constantine to write another one, in which he declares that it was only due to the actions of the people which had forced him to take on the burdensome office of pope.
He begs Pepin to bestow his friendship, promising that he would be even more in his debt than his predecessors were, and for the king not to pay any attention to any slanderous accusations that were being said about him and his election as pope.
Pepin refuses to reply to either letter.
On August 12, Constantine receives a letter, addressed to his predecessor Paul, from all the Eastern patriarchs apart from the Patriarch of Constantinople.
It is a synodical letter of faith, sent by Theodore, Patriarch of Jerusalem, and endorsed by Theodore, Patriarch of Antioch, and Cosmas, Patriarch of Alexandria.
It is also endorsed by a large number of the eastern Metropolitan bishops.
In it, it describes their support of the veneration of Icons, and their opposition to the iconoclasm being enforced by Emperor Constantine V. Constantine has the letter read before the Roman people, after which he forwards it to King Pepin.
