In this thread, its in post#35. They were brought in by Kings and Higher Nobles as outsiders with no loyalties to anyone but their employer, so they could be trusted to serve only their bosses, hence why they were referred to as 'The King's Jews'. It's that simple; no worries about spies from the Church, competing nobles, plotting relatives, etc., etc., plus they hated the peasants as well as everybody else, so no moral qualms about robbing everybody they could in the King's name. The idea there were no literate Europeans is just stupid propoganda; there were plenty; it was matter of who was loyal to who, as education was reserved for nobility, merchants, and clerics.