The materials for a study of the iconography of St. Thomas Becket still exist in great abundance. On the canonization of the saint in 1173, his cult evidently spread all over Europe with lightning speed, and the consequences of this were very soon to be seen in all the arts. Much of the artistic production of different countries and centuries relating to the personality and life of St. Thomas has, of course, perished: and in England, after the de-canonization of ‘Bishop Becket’, decreed by Henry VIII, a veritable war was, in 1538, declared on the innumerable representations of the saint then existing in this country, the proclamation enacting expressly that ‘his images and pictures throughout the whole realm shall be put down and avoided out of all churches and chapels and other places’. Where the destruction was not complete, defacement of varying extent was resorted to, as is clear, for instance, from the many illuminations of manuscripts in which the rendering of St. Thomas Becket has been disfigured or partly obliterated. But even so, as already mentioned, there still exists plenty of documentation on which to base a study of the iconography of St. Thomas Becket; and I have now for some time been gathering material with that end in view. In doing so my endeavour has been to work as systematically as possible, though, as all students of iconography can aver, chance often gives valuable help in the pursuit of our quest. I had an experience of the working of chance only recently when a visit to Salamanca, entirely unconnected with my interest in St. Thomas Becket, suddenly brought me up against an extremely interesting Romanesque church of San Tomás Cantuariense, from which, however, all traces of the representation of the saint had vanished, except a very commonplace figure of a mitred bishop in carved and painted wood of quite recent date. Even though I have kept photographers busy over a wider area of Europe than I could anticipate when first embarking on this task, I dare not hope that I have as yet surveyed my material with anything approaching completeness; but the data I have brought together are, nevertheless, perhaps sufficient to allow certain deductions to be made and certain lines of evolution to be laid down.