BERLIN.- The discovery of this intricately crafted rock crystal ewer recently caused a sensation on the British art market. The priceless object first made a stir in the press for being a 'sleeper', after being originally priced between ₤100 to ₤200 and mistaken by a smaller auction house for a French claret jug. At that initial auction it went on to fetch some ₤220,000. Evidently among the bidders that day were a few Islamic art experts, who rightly recognized the ewer's true worth as an exceptionally rare and valuable rock crystal vessel from Egypt.

The Fatimid dynasty ruled Egypt a thousand years ago. They founded the city of Cairo in 969 and were renowned for their fine craftsmanship. Rock crystal items were sold as valuable objects to European buyers very early on. Aachen cathedral has presided over two such objects since 1014. Once in Europe, the objects were often used as reliquaries, with the result that many of them became church treasures during the Middle Ages. Only seven ewers of such spectacular quality are known to exist in the world today.

When the priceless object went up for auction for the second time, at Christie's in October 2008, it was thought that it would go for between ₤10 and ₤15 million. Speculation mounted as to whether the Aga Khan, a descendant of the Fatimids, would purchase it, or the ruling house of Qatar. When the hammer fell, however, it became the property of the Keir Collection of Edmund de Unger.

The auction was a once-in-a-lifetime opportunity: the last ewer of this kind that was put up for sale was purchased by the Victoria and Albert Museum in 1862.

The priceless ewer now forms part of the group of loans from the de Unger family that will be on view for many years in the Museum of Islamic Art in the Pergamon Museum. It will be unveiled to the public for the first time on 24 June 2011.