the north.
As with the rest of the Roman Empire anything that happened in Rome ultimately filtered out to the periphery of the empire. Such was the case with Christianity and as a result Christianity spread fairly rapidly right to Spain and the first major diocese was established in the Zaragossa in the first century A.D.
As with all forms of religious imperialism which effectively Christianity was, Christianity moulded itself around a lot of the existing practices and nowhere was this more evident than Northern Spain especially with the Basques and the Galicians. The Basques especially had a problem with the Virgin Mary as they already had their own earth mother figure called Mari but as was the case Christianity moulded itself around a lot of the local pagan festivals.
Stephen Morgan writes about a great many Internet Travel based issues and more on the above can be found at Hoteles Galicia and Turismo Rural Galicia For a more complete overlook at Tourism in Galicia try http://www.turgalicia.es