This article is based on a lecture I was originally invited to deliver at Aberystwyth in the University of Wales in honour of the late Sir Thomas Parry-Williams (one of my earliest University teachers) and to do so on a topic which, I feel sure, would have met with his approval. He had himself studied with several of the most renowned and gifted scholars of the early part of this century, Edward Anwyl at Aberystwyth, John Rhys at Oxford, Rudolf Thurneysen at Freiburg im Breisgau, and Joseph Loth and Joseph Vendryes at the Sorbonne in Paris. He was one of the great scholarly and cultural heroes of my boyhood days and of my youth, a truly renowned scholar, literary figure and critic. His teaching days in the Department of Welsh at the University College of Wales at Aberystwyth spanned five decades, from 1914 to 1952 (he held the Chair of Welsh there with great distinction from 1920 to 1952). I treasure the memory of having been a member of a large post-war first year undergraduate class in his Department as long ago as 1947.