The art of engraving gemstones can be traced back to ancient Greece in the 8th century BC and earlier. Techniques passed down to the Egyptians and then to the Romans. There were major revivals of interest in engraved gems in Europe during the Byantine era, the Middle Ages, the Renaissance, and again in the 18th and 19th centuries. At each stage cameos and intaglios, these skillful carvings on a minute scale, were much prized and collected, sometimes as symbols of power mounted in jewelled settings, sometimes as small objects for private devotion or enjoyment. This gem is in the neo-classical style popular in the late 1700s and early 1800s, when taste in the arts echoed the subject matter and style of the Greek and Roman masters. Thousands of gems were made in this style in Italy and brought back by British Grand Tourists, who went there to visit the newly-discovered classical antiquities and archaeological sites. It once belonged to the collection of Prince Stanislas Poniatowski (1754-1833), a wealthy collector who commissioned about 2500 engraved gems and encouraged the belief that they were ancient. Many even bore the signatures of the most celebrated Greek and Roman engravers. The collection was sold in 1839 following Poniatowski's death, and later the scandal of its true background emerged and many gems subsequently changed hands for very low prices and were widely dispersed. The Poniatowski affair is often credited with causing a loss of confidence in the market for engraved gems, and the subsequent decline in the art from the mid nineteenth century onwards. Nowadays, ironically, the Poniatowski collection is of increasing interest as most of the gems were the work of a small group of neo-classical gem-engravers in Rome, including most probably the great Luigi Pichler (1773-1854),and have come to be regarded as important works of gem-engraving. The engravers of the Poniatowski gems took their subjects from classical literature, especially the works of Homer, Virgil and Ovid. It has not been established what the subject of this engraving is. Some sources identify it as Erechtheus, the ancient king of Athens, killing a serpent that attacked his son.