Prince Charles, Camilla and the Duke and Duchess of Cambridge at the Commonwealth Day Service just days before they gave up their positions as senior royals.
Spectators were particularly keen to see how the brothers and their wives interacted following countless rumours of major fallouts between them.
And fans were quick to pick up on a lack of any real conversation between the two couples, but one lip reader did manage to pick up one of William's 'bizarre' comments to his wife.
In his new book, Battle of Brothers, royal expert and author Robert Lacey recalls the day, which reportedly caused a lot of upset behind the scenes.Commenting on the two couples' behaviour on the day, he writes: "Nor could it be said that the two royal brothers made.
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