Reading and writing were rare skills in the Middle Ages. The only schools around were run by the Church, so most of the people who could read and right were clerics, which is were the English word "clerk" comes from.

Everyone knows about monks working at copying manuscipts, but most people who could read and write were employed keeping records. Every castle needed someone to write down the king's proclamations, lists of supplies, tax records and other documents necessary to keep the kingdom running.