The Last Prince Charles : BONNIE PRINCE CHARLIE<i> by Carolly Erickson (William Morrow: $19.95; 348 pp.) </i>

Under the wicked King Miraz, the children of C. S. Lewis’ Narnia were forced to learn their history from books as false as the most exciting novels and as dull as the most exacting scholarship. Carolly Erickson has not quite written a book that only King Miraz would love, but she has come dangerously close. “Bonnie Prince Charlie” strips the Bonnie Prince of any romantic appeal that clings to the last serious Stuart claimant to the British throne--but leaves us without an understanding either of Bonnie Prince Charlie as a man, or of the historical forces that doomed the Stuart heir to a futile life on the fringes of 18th-Century European affairs.

Like many of his ill-fated ancestors, Charles was at his best in moments of picturesque danger. After the defeat of his ill-starred attempt to invade England and reclaim the throne in 1745, he wandered in the Scottish wilds for months, sometimes dressed as a servant, sometimes as a woman, sleeping in the open field and waiting for the ship that would take him back to France. At one juncture, he was rescued by Flora MacDonald, a romantic Scot who later said that she would have done as much for Charles’ Hanoverian rival if he had needed it, and who fled from America after siding with the Tories during our Revolution. This is the moment that made Charles famous throughout Europe, and this is the moment that made him a sentimental favorite of posterity.

Misfortune usually brought out the best in the Stuarts. Mary Queen of Scots and Charles I faced the headman’s ax with equanimity; even the indolent Charles II managed to hide, very nobly and romantically, from pursuers in the branches of an oak. But long life was the bane of the family. James I was a truly undistinguished king best remembered for a bad book on witchcraft and the imprisonment and execution of Sir Walter Raleigh. Charles I drove Parliament to rebel; Charles II was in the pay of England’s deadliest enemy, Louis XIV; James II appalled even English Catholics by his ill-considered, illegal efforts to impose an unpopular religion on his Protestant subjects. Bonnie Prince Charlie, for his part, matured into a drunken, woman-beating lout.

We can only admire the Stuarts at a distance, or in their brief heroic moments. The more we know about them, the less patient with, and the less interested we are in them. To read a biography on such people is to lose sympathy, and usually interest, in the central figure: a daunting problem for popular biographers. The problem is worse in the case of Bonnie Prince Charlie; his royal ancestors lived at the center of power and fashion; the poor Pretender eked out a miserable existence at the margin.

The sources for Charles’ life are also unsatisfactory. He wrote short and impersonal letters, and the documents we have concerning him are generally the reports of ambassadors and spies. We know what color shirt and what color stockings he wore to dinner; we do not know what he thought or felt. Where Erickson tries to supplement the scarcity of historical records with psychological speculation, the results are unsatisfactory and thin. She tells us many facts about Charles, but does not help us either pity or admire him.

The sad truth is that Bonnie Prince Charlie is not worth the whole book; if Erickson was determined to write about him, she ought to have broadened her focus, and looked at the whole Jacobite movement. Absence made the heart grow fonder: There were many in England and Scotland who revered the Pretenders as the rightful kings, and Jacobitism long held a romantic fascination for some of the best minds in Britain. Where the power of Jacobitism lay, and why Charles was never able to harness it, would make a valuable and fascinating work of popular history.

It would also have corrected this book’s chief defect: its murky picture of the political context of Charles’ life. The reader who starts out knowing little about English politics in the period will learn little here; the reader who knows more will be put off by a careless tendency to represent the struggle as a personal one between the Stuart Pretender and the indolently porcine Hanoverians.

The ideal reader for this book is someone who wishes to write a romance novel loosely based on Bonnie Prince Charlie; such a reader will find a wealth of detail and information here and, lacking Erickson’s obligations to the historic record, can freely re-create the dashing Charlie of legend. The rest of us will do better to stick to older sources. Macaulay’s masterful, if malicious, “History of England” explains why the Stuarts lost their throne; Thackeray’s brilliant novel, “Henry Esmond,” explains why they could never regain it. These two books, one a frankly partisan attack and the other a historical novel, bring the reader closer to the spirit of the age of that era than Erickson does, for all her historical scruples and careful research.