Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Eminently readable introduction to the medieval Papacy

Schimmelpfennig provides the lay reader - and the historian - with a guide that is both accessible and relatively detailed on what is to most an obscure subject. At his best when discussing the political interactions between the papacy and the Carolingian/Holy Roman empires, this book opened up my interest in a host of contemporary issues, from the schism to the Cathar heresy. Good reading.PS - A must if you are a fan of Umberto Eco