Precisely when Christianity arrived in Roman Britain is not known.{{sfn|Petts|2003|p=29}} The province experienced a constant influx of people from across the empire, some of whom were possibly Christians.{{sfn|Petts|2003|p=29}} There is nevertheless a difference between transient Christians who may have arrived in Britain and a settled, Romano-British Christian community.{{sfn|Petts|2003|p=29}} Historian Dorothy Watts suggested that Christianity was perhaps introduced to Britain in the latter part of the second2nd century.{{sfn|Watts|1991|p=9}}
CircaAround 200, the Carthaginian theologian [[Tertullian]] included Britain in a list of places reached by Christianity in his work, ''[[Adversus Judaeos#Other Adversus Iudaeos literature|Adversus Judaeos]]''.{{sfn|Petts|2003|p=30}}TheHis contemporary, the Greek theologian [[Origen]] also wrote that Christianity had reached Britain.{{sfn|Petts|2003|p=30}} The accuracy of these statements can be questioned given that both writers had a strong rhetorical aspect to their work, which was designed to glorify what was still an illegal and underground religious movement.{{sfn|Petts|2003|p=30}} It is nevertheless possible that Tertullian and Origen were basing their statements on some reality.{{sfn|Petts|2003|pp=30–130–31}}
Christianity experienced slow and steady growth in the empire during the third3rd century.{{sfn|Petts|2003|p=3}} InHowever, the mid partnumber of thatBritish Christians was probably small, and it is unlikely there was any extensive church organisation before the 4th century.{{Sfn|Hylson-Smith|1999|p=39}} In the mid-3rd century, there was an intensification of the [[Persecution of Christians in the Roman Empire|persecution of Christians]], particularly under the Emperors [[Decius]] and [[Valerian (emperor)|Valerian]].{{sfn|Petts|2003|p=31}} These waves of persecution may have impacted the Christian community in Britain;{{sfn|Petts|2003|p=31}}. itIt is possible that [[Julius and Aaron]], two Romano-British martyrs mentioned in early medieval sources, were killed at this time. In 260, the Emperor [[Gallienus]] issued an edict that decriminalised Christianity, allowing the church to own property as a corporate body.{{sfn|Petts|2003|p=31}}
In 260, the Emperor [[Gallienus]] issued an edict that decriminalised Christianity, allowing the Church to own property as a corporate body.{{sfn|Petts|2003|p=31}} These shifts in the state's attitude to religion were accompanied by increasing political instability, financial difficulties, and a re-organisation of the armed forces and civil administration.{{sfn|Petts|2003|p=33}}