The Duke and Duchess of Sussex are a completely different kettle of fish. When they married in 2018 they were flavour of the month; flavour of the decade even.
They brought glamour to the Royal family - the dazzling alternative to the Duke's dutiful and rather staid elder brother and his equally reliable rock-steady wife.
But the sad truth of it is that life as the "spare" younger sibling isn't much fun. Yes, you get all the trappings of royal life but with none of the responsibilities as the head of state or as heir to the throne. And those responsibilities only diminish as you get older.
As Craig Brown pointed out in Ma'am Darling, his biography of Princess Margaret, the princess began life in 1930 as the third in line to the throne. If she were alive now, she would be behind Mia Tindall, Zara Tindall's daughter, in the royal picking order.
And so, as the crown slipped further from her grasp, all that was left for Princess Margaret was a life of sybaritic pleasure: rising just before lunch, punctuating the day with whisky and cigarettes, punctuating the year with holidays in her Mustique house, her dreary life briefly enlivened by a long affair with Roddy Llewellyn.
The Duke and Duchess of Sussex have both been good at carving out a role for themselves, with their mental health campaign and in Harry's Invictus Games for military veterans.
But, with their announcement that they are still stepping back from public life, there will still be huge gaps in the day, particularly as baby Archie grows up.
It is the gaps in the day that have so brought down other royal spares. Most famous of all spares, a self-proclaimed exile from royal life, was the Duke of Windsor after his 1936 abdication.
His life with the Duchess of Windsor became a dull merry-go-round of the world's glamorous, lotus-eating fleshpots.
From Palm Beach in Florida to their Paris home, life was a series of pre-lunch Martinis, lunch parties, a spot of golf, pre-dinner cocktails and dinner parties. In the Fifties, the writer James Pope-Hennessy, writing Queen Mary's biography, visited the couple.
He described them "like people after a cataclysm or a revolution, valiantly making the most of infinite luxury".
The Duke remained obsessed with his lineage: "You realise there are only three completely royal persons alive now. My sister, my brother and myself."
The Duke of Windsor wasn't the only spare brother of George VI. After the death of the Duke of Kent in a 1942 plane crash, the other surviving brother was the Duke of Gloucester.
Pope-Hennessy describes his Fifties life, too. The Duke had little to do except obsess about the weather, with drink playing a very great part of his life, Pope-Hennessy said.
Prince Harry isn't one for whisky and soda - his Hell-raising days are far behind him. And the metropolitan Duchess of Sussex is not one for vegetating in the English countryside.
So the big question now is one that faces all royal spares - what exactly will the Duke and Duchess do all day?
