According to GDP per capita, Spain is below Italy, but above Portugal. Has its position changed much over the last century? I would be interested to see a measure of that, but how far back is it feasible to estimate GDP per capita?

I don't know how Spain was affected by WW2, but they had a very nasty civil war just before WW2. I'm not sure if that's relevant to GDP per capita, though, because a war can sometimes improve the economy by leading to the overflow of a system in which progress is blocked by a relatively rich ruling class.

My grandparents would routinely call the 40s "The years of hunger" so you can guess which way it went.