From the Archbishop Isidor of Seville and his role in the Spanish Visigoth Empire to the Basque communist Dolores Ibárurri, spokesman for the republicans in the civil war against Franco - eighteen people are profiled in this book. The biographical sketches offer an alternative approach to dealing with Spanish history, the central developments of which are made visible here by dealing with influential personalities. A "key figure" is understood to be a person in whose life the contemporary characteristics and lines of conflict are particularly evident or whose actions had a significant influence on the development of the country. This also makes it possible to explore how Spain was anchored in general European history and to what extent it took a special path. The unity of Spain was already invoked by Isidor, but in the course of history there was and is always a lot of struggle for it. A society shaped by Christians, Jews and Muslims, as well as a colonial empire that was at times huge, always pointed beyond the narrower borders of the Iberian Peninsula. Accordingly, the fascinating biograms presented here offer not just one, but several keys to various facets of Iberian history from the Middle Ages to the present day.