London, Routledge & Kegan Paul, 1969 (first English edition).
Quarto, two volumes, xxxii, 428 and xii, 367 pages with 193 illustrations plus a colour frontispiece.
Purple cloth; extremities a little bumped (with light associated creasing to the bottom corners of the initial leaves of Volume I); ownership signatures; a very good set with the dustwrappers a little rubbed and creased, and with a small chip to the foot of the spine of the Volume II.
The eleventh volume in the A.W. Mellon Lectures in the Fine Arts.