Who is Conde Alvaro de Luna from Iberia: Spanish Travels and Reflections and what is their importance?

The conde became a confidant of Isabel the Catholics father, King Juan II. He used his connection to gain power and soon had so much money that he became the most "notorious legal thief" in Spanish history. The Queen, Isabel of Portugal, was so concerned that she had her husband find some charge to arrest him. He was executed and buried in the chapel.