The masterpieces of Minoan art are not what they seem. The vivid frescoes that once decorated the walls of the prehistoric palace at Knossos in Crete are now the main attraction of the Archaeological Museum in the modern city of Heraklion, a few miles from the site of Knossos. Dating from the early or mid-second millennium BC, they are some of the most famous icons of ancient European culture, reproduced on countless postcards and posters, T-shirts and refrigerator magnets: the magnificent young "prince" with his floral crown, walking through a field of lilies; the five blue dolphins patrolling their underwater world between minnows and sea urchins; the three "ladies in blue" (a favorite Minoan color) with their curling black hair, low-cut dresses, and gesticulating hands, as if they have been caught in mid-conversation. The prehistoric world they evoke seems in some ways distant and strange—yet, at the same time, reassuringly recognizable and almost modern.

The truth is that these famous icons are largely modern. As any sharp-eyed visitor to the Heraklion museum can spot, what survives of the original paintings amounts in most cases to no more than a few square inches. The rest is more or less imaginative reconstruction, commissioned in the first half of the twentieth century by Sir Arthur Evans, the British excavator of the palace of Knossos (and the man who coined the term "Minoan" for this prehistoric Cretan civilization, after the mythical King Minos who is said to have held the throne there). As a general rule of thumb, the more famous the image now is, the less of it is actually ancient....