The Elgin Marbles were sculptures which were a part of the Parthenon. They were removed by Thomas Bruce, Earl of Elgin (location), and taken to the British Museum. This act was, according to the Eighth Doctor, controversial.
In 1921, Martin Donaldson showed the marbles, among artifacts at the British Museum, to Liv Chenka. (AUDIO: A Life in the Day)
In the late 22nd century, during the second 22nd century Dalek invasion, the Monk stole the marbles, among other pieces of art. (AUDIO: Lucie Miller)