GLADYS, DUCHESS OF MARLBOROUGH by Hugo Vickers Holt, Rinehart & Winston; 308 pages; $12.95
One of the great lessons of fairy tales is to mind what one wishes for: one may get it. In 1895 a schoolgirl named Gladys Deacon read about the marriage of the reluctant Consuelo Vanderbilt to the Duke of Marlborough and determined that some day she too would marry well.
Gladys had no reason to think of marriage as a binding contract. Her own parents, part of that affluent late Victorian world of American expatriates, parted in sensational circumstances when...