In those times, the pope was chosen from among the priests and deacons of Rome and never from among bishops from other dioceses . At the time, the Pope - by definition the bishop of Rome - was considered as such only from the day of his ordination. Since Stephen was never consecrated as a bishop, he was not considered a legitimate Pope and therefore, omitted from all lists of popes. His immediate successor, also called Stephen, is as a rule numbered Stephen II, since the name Stephen had already been borne by Pope Stephen I (254-257).