This large green urn was given as a gift to Queen Victoria in 1839 by Emperor Nicholas I, to thank her for the way in which his son Alexander had been welcomed in England the previous year. It was placed in the Grand Reception Room of Windsor Castle, and has remained there ever since.

The urn itself is constructed from limestone. The distinctive green malachite is a mineral first mined in the Ural Mountains of central Russia. Because of its brittle nature, it can only be used as a veneer on large objects such as this.

The urn was made at a cost of 40,000 roubles in 1836. This equated to around £20,000...