“The Master of Arts (MA) took another four years and earned the Master the right to teach at any other university in Christian Europe (ius ubique docendi)—today’s Master’s is usually a one-or two-year degree. Then, for some students, another six to ten years of study culminated in a Doctorate in law, medicine, or theology (the equivalent of today’s PhD): the first two, even back in the Middle Ages, being nicknamed ‘the lucrative sciences’; the last, being rather less well-rewarded in this world, was at least styled ‘the queen of sciences’.”
from “Universities and Colleges: A Very Short Introduction” (Very Short Introductions)” by David Palfreyman, Paul Temple