One of the reasons that Muslim rule over Spain is regarded as colonization, but not the earlier Visigothic rule, is that the Goths had very little cultural impact on local society. For example, the Iberian Romance varieties were never replaced by Gothic, rather the Goths quickly assimilated to Iberian Romance. In Andalusia, on the other hand, there was a gradual process in urban areas of shift from Romance to Arabic that was only reversed after Muslim rule ended. In religion, the Visigothic rulers soon converted from the Arian Christianity upheld by the Goths to the Nicene Christianity of the local population, while under Muslim rule the inverse often happened and Christian Andalusians converted to the Muslim faith of their rulers.