Like the band sported by Kate Middleton, it was an eternity ring.

Word reached Prince Rainier, who was having none of it.

This article first appeared onTatler.

Prince William Kate Middleton

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Kate Middleton and Prince William surprised the country with a video celebrating the success of Team GB at the Paris Olympics

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Grace Kelly on the set ofHigh Society, showcasing the iconic engagement ring gifted to her by Prince Rainier of Monaco

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Grace Kelly, en route to Hollywood for movie work, strikes a pose to show off the engagement ring given her by Prince Rainier III of Monaco as she arrives in Chicago

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Grace Kelly dances with Frank Sinatra during a scene fromHigh Society