The King's Two Bodies
http://www.amazon.com/Kings-Two-Bodies-Ernst-Kantorowicz/dp/0691017042/ref=sr_1_1?s=books&ie=UTF8&qid=1423156526&sr=1-1&keywords=the+king%27s+two+bodies
This is a great, unique study of the evolution of oriigins of the modern corporation from the fall of the Roman Empire through to the Renaissance. Scholarly and erurdite--easier reading if one glosses over much of the esoteric footnotes containing various references in Latin, Germain, etc.
For those interested in the role of the church and medieval legists in the transition of kingly and corporate legitmacy from the religious to the secular, as well as the wide influence of "corporation" in all of our daily llives to this day, this book is a must-read.