Women are politics,"" Talleyrand once remarked. He might have been speaking of the subject of this sympathetic biography-- Dorothy, Princess of Courland, Countess of Perigord, Duchess of Dino, Duchess of Talleyrand, and Duchess of Sagan. Born beautiful, immensely wealthy and aristocratic, Dorothy was also uniquely intelligent. In the interests of practicality, she was married to the hapless heir and nephew of Talleyrand who proved her inferior. His uncle, on the other hand, made her his hostess at the Congress of Vienna. From that time until his death more than twenty years later, Dorothy was his most constant companion, his confidante, amanuensis and aide in political intrigue... The Browning-esque title of this translation of a 1956 book does not suggest the thesis explicit in the original French title, Le Dernier Amour de Talleyrand. Apparently Dorothy was of more than political interest to the aging Prince. Yet her most recent biographer, Philip Ziegler (The Duchess of Dino- 1962) found no proof whatsoever that Dorothy was Talleyrand's mistress. Ziegler's work, better documented, is also better written, and therefore of greater interest to both scholar and general reader.