Related to the Second Reformation in Spain are the following historical facts. (Very compact, so don't expect this to be exact!)

In the beginning of the 18th century the Spanish monarchy went over from the Austrians to the house of Bourbon. (Spanish war of succession 1701 - 1713) Now those Bourbons were a very reactionary, conventional family. In France the French Revolution had brought a lot of changes, including many secular ideas, pertaining to what they choose to call: the Enlightenment. Those ideas started to filter slowly into Spain, so that at the beginning of the 19th century Spain was ready for a liberal constitution. 

In the meantime Napoleon - who was born in Ajaccio on Corsica in 1769 - came to power in France, and far from being content with that, he started out in order to conquer Spain. Which indeed he did. But of course we was defeated in the end, and the Spanish people deemed King Ferdinand VII fit to be a King who could give them a constitution. So in 1812 the Fist Constitution was drawn up and proclaimed in Cadiz. (Nearby San Fernando claims the same honor, because the Constitution was sworn in there.) This first Constitution was commonly called La Pepa, because the date it was applied fell on the day of Saint Joseph, San José, Pépé for short. 
Alas! The fact that a Constitution exists cannot guarantee its effectiveness. 
The 19the century turned out to be a very unsettled one in Spain, where rivaling groups in society in turn tried to seize and hold the power. Both Liberals and Conservatives were divided in themselves, next to them Carlists and Republicans wouldn't give each other the time of day, and each party had its own ideas about religion and its place in society. Thus the concept of freedom of religion was interpreted in many a (very different) way in de course of time, varying from: there is freedom of conscience and religion for every Spanish citizen (a very rare phenomenon) until every Spaniard is a (Roman) Catholic, full stop, and strangers may - by the Grace of God - practice their religion, but never in public...

Now Ferdinand VII turned out to be an utterly conservative man, and liberalism stayed put until the latter quarter of the 19th century.
Ferdinand's daughter, Isabel II, was in political sense no less conservative than her father, being under the influence of her minister, who were (one at a time) her lovers as well. In this respect the people showed more conservatism then the queen, so the was disposed of in 1868. The generals Prim and Serraon, who revolted against her and her ways of life, were liberals, but preferred a monarchy, be it under certain conditions. Prim is said to have stated: "To find a democratic king in Europe is as difficult as to find an atheist in Heaven.''
The Crown was offered to Amadeus of Savoy, who tried to comply for about a year,  but he proved no success, so he went of his own accord, rather than to risk bloodshed because of him.
So in 1873 the First Republic was called into existence, after Don Carlos had started - in vain - the Second Carlist war in 1872.
This First Republic meant that for the first time since the inquisition (which was abolished under Ferdinand VII!) there was freedom of religion on Spanish soil!

But the Republic was no great success either, and in 1874 the house of Bourbon reappeared on the throne, in the person of Alonzo XII, a son of Isabella. At once there was an end to any freedom of religion, and the Roman Catholic religion was reinstated as the only and official one. That is to say: there was freedom of conscience, but there was no possibility to propagate the belief, and who thought otherwise was persecuted.

In 1886 Alfonso XII was succeeded by Alfonso XIII, who was a king of no importance, whatsoever. Under his reign there was in fact a dictatorship of José Antonio Primo de Rivera, 1923 – 1930. In 1931 the king is thrown out of the land, by a sort of revolutionary outbreak of the left wing. The king did not fancy a civil war to save his throne, and abdicated in good harmony, after which he sailed for England.

Now Alfonso XIII had a son Jaime, who was deaf and dump, the father of the king of our days. His title was Count of Barcelona.

In 1931 a Second Spanish Republic was proclaimed after the abdication of Alfonso XIII, which deteriorated in the course of the next three years into a terrific struggle for power between all the parties in the country.
This Second Republic had done away with the Roman Catholic church as an institute of State, which created an interlude of freedom of religion, which lasted until 1936.
Of course the Protestants were in favor of this freedom of religion, so in latter days they were blamed to be left wingers. And 'so' against 'the Patria', which made that they have been persecuted severely under Franco, irrespective of their real thoughts and preferences. The odium of being no real Spaniard had never left them, until this very day.

In 1936 the Communists seemed to make and attempt to seize power (La Pasionaria) and so the revolution started – in Morocco – under General Franco.  

This insurrection was against the republican government, which had not much say. The Communists strove very calculatedly for a seizure of power. These are the ingredients of the Spanish Civil War 1936-1939, which was won in the end by Franco, who usurped the power and titled himself Caudillo, which means (commander-in-)chief. He restored the Roman Catholic Church in its old position, linked to the State, and the monarchy as well, but as yet without a king. Jaime was not deemed worthy of the throne, and his son Juan Carlos was still under Franco's tutorship, and was not until Franco's latter days pushed to the front. The Protestants have no feelings for him. The others not much more, until very much later. 

Whenever Franco taken hold of a part of Spain, the Protestant Churches were closed, so were the schools, the ministers were killed, chased away, exiled, silenced. They suffered very much. 

In 1939 the Civil War ended. Between 1936 – 1939 many 'red' boys from abroad fought and died on Spanish soil, included many boys from Holland. And Hemmingway.

As said before: most of the Protestants were on the side of the socialists, because those proposed the abolition of the blending of State and (RC)Church. This means that they were seen as enemies of the State. They shared this fate with a part of the lower clerics in the South, which had seen the misery of the people, and taken them to heart. The literature of the trade union was often printed under the cloak of those 'red' priests. 

Apart from that English and American spies infiltrated via the Protestant churches, which didn't help much either. Ever since England took Gibraltar, there have been Anglican churches. They were quite a source for knowledge in Spain for the Protestantism in Spain. So the Protestant churches in Spain were at that time rather closely linked with Gibraltar (the port to freedom).

The sores of the Civil War continue to tear through the churches. One of the major grudges of the elder Protestants, is that the enormous monument for the fallen, (the dot left from the middle, just above the mountains) erected by Franco in the Valle de los Caídos, not far from Madrid, was exclusively meant for those fallen at Franco's side. It could have been a monument of reconciliation, it turned out to be for them at least a monument of discontent. An argument directed against the RC Church in Spain as well, because they should have moved thither from her calling based on the gospel of Jesus Christ. 

Spain kept it self  out of World War II. The good relations between Franco and Germany made it possible that Spain remained neutral territory. (So that is why the many European fugitives that tried to reach England by way of Spain, got a could shoulder in Spain, and were interned if captured.) By his abstention of the war Franco weakened the European position. (During the Civil War a German 'Condor legion' was lying in Spain, which belonged to the German troops that want back to Germany in 1939, because Hitler needed them there more.) 

Juan Carlos was appointed king by Franco before his death, and was considered a weakling by those around him, but he gained some respect when he prevented a general uprising soon after his coming to the throne. By the third Millennium he has retained that respect, and gained some more.
He never was found interested in the Protestant minority, but his wife had herself informed by the best men available.  go up