The British Museum on Friday said it lent one of a collection of Greek sculptures to Russia, reigniting a battle between the U.K. and Greece over who owns the 2,500-year-old works known as the Elgin marbles.

Greece reacted with fury to the loan of the headless, reclining sculpture of the river god Ilissos to Russia’s State Hermitage Museum in St. Petersburg. It is the first time one of the sculptures has left the U.K. since they were removed from the Parthenon in Athens more than 200 years ago.

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