I think of them as Dave’s Faves, a class to rank alongside Tony’s Cronies.

As a depressing raft of these political place-persons prepare to take their seats in the Lords, let us look back on a time when such preference was given not on the basis of favour, but for an inherited grace and grandeur (perceived if not actual).

The hereditary peers of my childhood, the ones close to home, were the sixth Marquess of Exeter and the 10th Earl Fitzwilliam.

Lord Exeter resided at that wonderful Elizabethan pile Burghley House, in Stamford, the intended UK base for Hermann Goering once certain matters had been attended to.

Alas for him, posterity (and Winston Churchill) had other ideas.

Fitzwilliam lived on the 23,000-acre estate at Milton Hall, near Peterborough, where his wife, Lady F, was walking evidence of the old adage that you can never be too thin or rich.

Her second-hand clothes stall at the annual Tory fete, packed with designer labels, was a must for local ladies, slender ones.

Occasionally, for grouse shooting and the St Leger, they moved north to 365-room Wentworth Woodhouse in Yorkshire, by some way Britain’s largest private house.

David Exeter survives, in one sense, in the character played by Nigel Havers in Chariots of Fire. This was Lord Burghley, as he was before his elevation to the peerage, the winner of the 400-metres gold medal at the 1928 Olympics.

Now Tom Fitzwilliam looks to be in line for posthumous fame, too, as a character in a forthcoming BBC television series called Black Diamonds.

This is set to become – ahem – Downton Abbey on speed and, at a guess, with considerably more class.

The action occurs among a massively moneyed milieu and features events so amazing that Lord Fellowes – another of Dave’s Faves – would have rejected them as being preposterously unlikely for the Crawleys.

I know this because I have read the book on which Neil McKay – the writer of another astonishing story, that of Fred and Rose West, in Appropriate Adult – has based his script. Indeed, I have read it twice.

I applauded Black Diamonds, by the Oxford-educated historian Catherine Bailey, when it appeared in 2007.

Last week I ripped through it again to remind myself how good it is. The title is a reference to coal, the presence of which on the family estate, on a huge scale, was the basis of the Fitzwilliams’ extraordinary wealth.

Billy Fitzbilly, as the seventh Earl was known – his first name, rather absurdly, being William – inherited the equivalent of about £4 billion when he assumed the title in 1902 on the death of his grandfather.

The story begins in startling style with this inheritance, since it was argued by a powerful phalanx of the family, including his poisonous Aunt Alice, that Billy was not the heir at all but a changeling.

It was alleged he was placed in the bed of his drugged mother moments after she had given birth to a daughter.

All this occurred (or not) in faraway Canada, on the shores of Lake Superior. The father, Viscount Milton, who died in 1877, was a Victorian explorer.

Billy won his inheritance (though Bailey hints that he should not have) and lived to enjoy it lavishly for a further 40 years.

Expertly handled in the book, as one hopes it will be on TV, is the contrast between the family’s life and that of their workers.

Space prevents further exposition, except to say how things went wrong after the death of the eighth Earl; killed in a plane crash in 1948 with his lover ‘Kick’ Kennedy, sister of the future US president.

His successor was a hopeless alcoholic. When he died in 1952, Tom Fitzwilliam successfully went to court to wrest the title, calling his older brother, Toby, a bastard.

He left no male heir, so the title became extinct in 1979.

Wentworth Woodhouse survives, however, and is soon to be given a new lease of life for anybody able to fork out £42 million for repairs.

Milton goes on, too, its current chatelaine being – by an odd coincidence – a descendant of another great coal baron, the Earl of Durham.