The ceremonial return of 21 Benin bronzes to Nigeria by Germany last month gave the latest powerful signal of how fast the international tide is turning on the repatriation of looted art. The German handover followed an American one two months earlier, when the Smithsonian Institution signed over 29 bronzes in Washington. Both ceremonies turned the spotlight once again on the country whose army was responsible for seizing the bronzes in the first place: Britain.

The restitution of artefacts is an old bone of contention that has left the British Museum, in particular, beleaguered on all sides. The defence has often focused on how works arrived in museum collections: whether they were honestly acquired or stolen by individuals or armies. In the case of the Benin bronzes, there is no ambiguity. They were looted in 1897, when British forces sacked the Benin kingdom, in modern-day Nigeria, burning down the royal palace, exiling the oba (ruler), and seizing all royal treasures.