see https://en.wikipedia.org/wiki/Christianity_in_the_6th_century

Islam doesn't exist yet (- 570: Birth of Muhammad.)

in general: assume religion to be less powerful. Christianity does not yet rule over Europe, and there is quite a bit of competition.

Gaul & Spain / Galliae & Hispaniae

Conversion to christianity ongoing (300-600).

Britain / Britannia

West: 300-600
East (Anglo-Saxons): 600-800

Germany

Saxons and Frisians: 600-800