With his usual intelligence and grace, Giblin (well-known for his award-winning nonfiction) covers the extensive history of a popular subject, once again illuminating some fascinating byways of social history with skillfully assembled facts. Recounting tales of unicorns from Chinese legend, Indian myth, and ancients in the Western world from Deuteronomy to Julius Caesar, Giblin sets them in the context of a world where many creatures were rumored but not actually seen (e.g., the rhinoceros). The book's heart is a detailed discussion of the unicorn tapestries at the Cloisters in N.Y.C. (reproduced in a color insert)--their history, their intricate symbols, the medieval Christian beliefs they exemplify, and their hold on the 20th-century imagination. Final chapters discuss uses of unicorns' (narwhal's) horns; how scientific inquiry discredited belief in the mythical beast and its powers; its role in current popular culture; and even some comments on the endangered species that generated the myth in the first place. As always, Giblin has a firm grasp on his subject's many ramifications and links them with clarity and extraordinary insight, providing a splendid model of the branches of knowledge enriching each other. Though unicorns seem ubiquitous, this is the first book for young people to explore their lore in depth. In addition to McDermott's soft-pencil reconstructions of ancient descriptions (e.g., ""Pliny's unicorn""), many b&w photos of historical artifacts are included. Bibliography; index.