In three previous novels, Shelby delineated the murky bloodletting in the 12th century Holy Land, and returned to England with the death of Richard I. Here he takes on the embroilments of King John, again with more fastidiousness in period speech and ambiance than most--perhaps a bit too much. Although the reluctant signer of the Magna Carta seems, like Richard III, on the brink of post-Shakespearean rehabilitation, Shelby convincingly portrays John as a ""wolf""--skilled in military or diplomatic ambush, helpless in the open. Mother Eleanor of Aquitaine, in her 80's here, loved his brother Richard better, which led John into dressing up like a peacock and taking great delight in his personal coups. This is also the story of that old warlord, the Earl of Pembroke, William Marshall, adviser to both Richard and John--a disciplined, if caustic monitor of the unloved King--and John's unpleasant young wife Isabelle. John's losses and gains pile up: crafty barons address him as ""King"" and increasingly refuse him arms and money; there are bloody castle-by-castle battles and sieges in France; John murders his nephew; and then there's that document signed at Runnymede which gave Englishmen the first codified limitation of monarchical power. A responsible, if somewhat dry, fictional assessment of the times and John's ""bare-picked bones of majesty.