There is no mistaking the overwhelming affection with which the Duke and Duchess of Cambridge have been greeted on their inaugural royal visit to Canada. That is, in part, because everything they are doing resonates with a shared history.
Take their first engagement: a visit to Canada's National War Memorial was a poignant reminder that Canadian troops had served alongside the British in the two great world wars of the last century. Government House, where the couple stayed in Ottawa, was visited by King Edward VII when he was Prince of Wales, in 1860. In 1951, Princess Elizabeth and Prince Philip were entertained there, secretly bringing with them a draft proclamation in case George VI, already very ill, should die while they were away.
She was absolutely right. When the second in line to the throne travels to Canada, it is like visiting family rather than some foreign country – not least because his grandmother, the Queen, is head of state in Canada. Such is the invisible strength of the Commonwealth, the association of independent countries that emerged out of the wreckage of the British Empire at the end of the Second World War.