Outsiders and the possibility of invasion played an important role in apocalyptic imaginations. In the last days Satan would rally Gog and Magog from all corners of the globe to come into battle (Rev. 20,7) – a statement which resonated well with Old Testament prophecies in Ezekiel (Ezek 38-39) and Jeremiah (Jer. 1,14) about Gog of Magog – an evil from the North – coming to punish Jerusalem for its sins.

In the last century of the Roman Empire it was easy for some Christians to believe that the various ‘barbarian’ groups who invaded or settled in the Empire were realisations of Gog and Magog. Some talked about the similarity of the Gothic names ‘Getae’ and ‘Massagetae’. But we only really know this from the counter-action of Jerome and Augustine, who both sought to undermine such associations.

An important new phase came in the seventh century. The mysterious Pseudo-Methodius explained that the Arab conquests in the middle of the century paved the way for a Last World Emperor to reunite the Roman-Byzantine Empire. He would then lay down his power just as Gog and Magog came from the North to assist Antichrist. The popularity of Pseudo-Methodius assured a long-lasting blurring of the traditions from the Old Testament and Revelation.

This can be seen most dramatically in interpretations of the viking raids from the late eighth century onwards. Just before then one writer, Aethicus Ister, had joked about what would happen if the barbaric peoples of the North – clearly associate with Gog and Magog – ever attacked the rich south. When they did from 793 onwards, the words of Jeremiah in particular sprang to writers’ minds.

There was more to the tradition than Gog and Magog. According to the Evangelists, Christ himself had warned about nation rising against nation in the last days. He had also asserted that the End would not come until the Gospel had been preached unto all peoples. We therefore find that many people challenged anxiety about outsiders and invasion into moral reform (for instance, in the work of Wulfstan of York) or missionary work (by Anskar, for example).