Historian Gelardi (Born to Rule
) focuses on the fates of three pairs of royal mothers and daughters: Isabella of Castile and Catherine of Aragon, Maria Theresa and Marie Antoinette, and Queen Victoria and Empress Frederick. The unusual melding of Spanish, English, Austrian, French and Prussian history into one sweeping project is done with remarkable clarity and verve. Excerpts of her subjects' letters are integrated flawlessly into the sequence of events. Gelardi is also skilled in placing actions within the larger historical framework of international relations, as well as genetics—Gelardi traces the devastating effects of hemophilia on royal families in one of her most interesting tangents. The personal relationships portrayed are layered and complex, and tidbits regarding fashion and Queen Victoria's childhood love of dolls are not to be missed. Gelardi's incessant need to justify connecting the three monarchs and their daughters through similarities in personality, political accomplishments and unusually loving relationships is annoying, but she still produces an excellent, comprehensive study of six fascinating women and the troubled times that shaped their lives. 16 pages of color photos. (Dec.)