The papacy of Zephyrinus ends. Callixtus I is elected as the sixteenth pope, but is opposed by the theologian Hippolytus who accuses him of laxity and of being a Modalist, one who denies any distinction between the three persons of the Trinity.

Trinity
Sabellianism
Hippolytus of Rome
Theology
Pope
Pope Callixtus I
Pope Zephyrinus