While such ''Curses'' were readily seen in Ancient Times (''Before Christ''), the theory of The ''Book Curse'' was probably most related to The Medieval Era. Books were very expensive to produce and were a ''sign'' of a persons ''wealth'' and ''education''. Theft was a very real issue with Books in the 15th Century AD. As such, even ''rational'' and ''learned'' thinking and beliefs gave way to the old-fashioned and ''time honored'' Curse. Often to ''protect'' One's valuable Library, an Owner would have a specialized ''Curse'' written into the Books Front or End Cover. This curse harshly condemned a potential theft. Often, Christian Excommunication was threatened (if owned by The Church), with ''promises'' of ''demonic attack'' by more private Owners. Given the state of superstitions during The Era One had to0 be careful ''what kind'' of curse was written and of course, ''where'' such a curse was ''procured'' (One had to be careful of Sorcery Charges!) Many examples have survived today.