In 1834 John Murray published Bubbles from the Brunnens of Nassau. It was the first cloth-bound book ever published with a full pictorial cover.
In his book The Collector’s Book of Books Eric Quayle says:
“By 1834 the battle was won, and it was then that the first fully cloth-bound book appeared which featured pictorial covers. This was a landmark in book design, and must have caused a considerable stir in the publishing world. The idea seems to have been the brain-child of the author, the eccentric Sir Francis Bond Head.”
The image above comes from Princeton University’s recently acquired copy of the first edition. Interestingly enough, their copy is in full vellum and not cloth leading me to wonder if it also the first book bound in vellum that sports a full pictorial cover.