Adelaide Violet Cicely Monson (1870-1955) married George Leveson-Gower, a politician.
Horace Jones (1978) records this bookplate as signed W.P.B. and dated 1919. It is not initialed W.P.B. and it is dated 1909 in the lower right margin. This could be a trial proof but I suspect not, as another record suggests it is dated 1909. The zero is not very distinct. Lee (1998) in his monograph on
Bookplates by Robert Osmond states that the scene is Chateau de Cony viewed through a Norman window, but I can find no such Chateau and no place called Cony in France. There is a Chateau Cany, but it looks nothing like this.
Bookplate (click to enlarge)