The Viking invasions of the eighth and ninth centuries reintroduced paganism to North-East England, leading in turn to another wave of conversion. Indigenous Scandinavian beliefs were very similar to other Germanic groups, with a pantheon of gods including Odin, Thor and Ullr, combined with a belief in a final, apocalyptic battle called Ragnarok. The Norse settlers in England were converted relatively quickly, assimilating their beliefs into Christianity in the decades following the occupation of York, of which the Archbishop had survived. The process wass largely complete by the early tenth century and enabled England's leading Churchmen to negotiate with the warlords. As the Norse in mainland Scandinavia started to convert, many mainland rulers recruited missionaries from England to assist in the process.