I have recently been reading Dogs of God: Columbus, the Inquisition, and the Defeat of the Moors by James Reston Jr and enjoying it immensely. Reston tells the story of the late 1400s in Spain and how crucial this period was in so many ways.
While the Spanish empire was expanding around the world, internally it was turning on itself as the Inquisition increased its persecution of heretics and Jews. Reston has a very readable style and is not afraid to use comedy at times as he talks about how a very cosmopolitan empire could become so inward looking.
An interesting book that people should look out for and read about this important time in the history of Europe.