With a healthy, partially-exposed bust on the cover, some she-was-torn-between-love-and-duty ads, and a blithe unconcern for facts, "Eleanor of Aquitaine" could have led the best seller lists. As it is, Amy Kelly has written not a historical novel but a scrupulously documented history of the twelfth century. "Eleanor of Aquitaine" is a sober account of a game girl.

The richest marriage prize of the middle ages, Eleanor married two kings and was the mother of two more. Cultured, spirited, and ambitious, she was an amazon on the Second Crusade, a lover at the Court of Poitiers, and a ruler ("by the wrath of God" as she put it) in her old age. Intellectual revolt, crusades, and struggle between church and state, marked the twelfth century, and Eleanor managed to have something to do with all of them. Miss Kelly user her as a "binder" for her history.

When she became dissatisfied with her first husband, Louis VII, ("I thought to have married a king, but I find I have wed a monk"), Eleanor divorced him. Adding the Plantagenet tag to the Capet one she already possessed, she married Henry II of England, twelve years her junior. Her sons were Richard the Lion-Hearted and John Lackland.

In a way, the Capetains and Plantagenets were amateur gangsters; they were land-grabbers and money-grubbers, they ignored the sterling principles of the feudal code, and they were usually in trouble with the Church. "I would sell London," said Richard, "if I could find a purchaser." Richard's atrocities get objective reporting, as do the incidents which have become legend, such as the meeting between Richard and Robin Hood.

Fair Rosamond (Henry's well-known paramour), whose famous hardships in a bower have inspired romantic writers for ages, gets only cold glances from the author. The story of the jealous queen's proffer of the dagger and poison bowl is discarded; for Rosamond, "flower of the world," died young in pious retirement. Still, Miss Kelly captures both the glitter and the solidity of the Middle Ages.

"Eleanor of Aquitaine" is really more a story of the Angevin Empire than a biography of Eleanor, for it strays from Eleanor for hundreds of pages to report Henry's consolidations of his vast holdings. For a biography, there is not enough Eleanor; for a history, almost too much.

Those who still harbor a sneaking suspicion that this is a historical novel have only to turn to the 30 pages of notes and bibliography at the back.

In the first modern, complete account of Eleanor, Miss Kelly has presented a sound piece of scholarship in a careful, selective style. It seems to be in a class by itself.