75 years ago this week, on the 18th July 1936, the Spanish Civil War began, entering Spain into four years of war and forty of facist rule under General Franco. Although in Europe and worldwide, World War II still casts a long shadow, the Spanish Civil war probably cast an even longer shadow over that country. The Spanish had to wait until the mid 1970s before they had a vote again. Their war was particularly nasty in that it pitted neighbour against neighbour, and even family members against each other. The depth of feeling the war and the Franco era still evoke can be seen by the number of comments on this newspaper article - http://www.publico.es/espana/387587/una-sombra-larga-que-se-proyecta-hasta-el-presente.
It is easy in hindsight to paint one side as the bad guys, but the truth is that both groups did some pretty bad stuff before and during the war, and that either side could probably have averted the war if they had wanted to pursue a diplomatic solution. Wikipedia has a good article covering the causes and events of the war in a lot of detail - http://en.wikipedia.org/wiki/Spanish_Civil_War