The institution of the Christian church has been present in the Iberian peninsula from the very beginning of the church. Early traditions relate evangelization by Saint James and others. While these reports were from the second and third centuries, they were widely believed in Spain and fed into later belief of the return of Saint James body after his martyrdom.
While there is some physical evidence of churches during Roman times, the churches were not large nor did any (that I learned of) survive. In the 5th century AD, Roman Iberia was conquered by the germanic Visigoths. They established some cathedrals but while these were preserved through the Islamic conquest they weren’t considered adequate by later Christian conquerers. Their rule was also complicated by their adherence to a heretical form of Christianity (Arianism) that kept them from establishing a coherent religious society. After the Islamic conquest in the 6th and 7th century, Christians could worship in their churches but were under some pressure to convert and few new churches were built. Those that were built were interesting amalgams of Christian and Moorish architecture which was called Mozarab. Unfortunately, most of those were rebuilt after the reconquest because they were considered inadequate or simply to purge the prior Moorish influence.
One is struck by the sheer number of churches that were built between 600 and 900 years ago that still survive. In northern Spain, the vast majority of surviving churches are romanesque in design. There are scattered pre-romanesque churches, but the vast majority are romanesque. These range from the many community or parrish churches which are present in all of the small towns to magnificent cathedrals in the larger cities. I will need to research where all the money for these churches came from. In larger cities like Leon and Burgos, there are huge gothic and baroque cathedrals that obviously benefited from New World gold. But the funding for all the romanesque churches still puzzles me.
The gothic cathedrals are as immense and magnificent as money can buy. The beautiful stained glass windows, the ornate altarpieces, the awe inspiring porticos (you easily run out of superlatives) demand your appreciation. Many (most?) were built on and/or with the stones from earlier churches. The Cathedral of Saint James in Santiago was built on top of an earlier romanesque cathedral about half the size of the current building. And this was built on top of an even earlier church which was the first building to house the relics of Saint James.
Most of the gothic cathedrals have layers of artistic periods layered upon the original construction. Side chapels added to commemorate the support of various rulers. New asps and transepts, new altarpieces, new or renovated or removed choir areas. All with various elements of gothic, baroque or newer styles. Some are a little ostentatious but they are all striking. I imagine it creates some issues to the restorationists as to what time periods to retain and to restore to.
One reason that the churches of northern Spain have survived so well is that most regions of northern Spain did not suffer destruction due to war. Spain was spared from World Wars I and II and was little affected by the Spanish Civil War (except the Basque region). Other advantages (?) were the generally poor Spanish economy over the last two centuries and immigration from the region. There wasn’t the money nor the population pressure to tear down old churches to reuse the land. You see very few ‘newer’ churches.
I loved the churches of the Camino. They are quiet, usually dark (thank you romanesque windows), and still. It is wonderful to go into the churches and simply listen. Listen to silent footsteps that wore down the stone walkways. Listen to the silent echos of prayers of the priests and faithful that lived centuries ago. Listen to your heart as you contemplate or pray. It was one of the best parts of my Camino