Would you choose a good night out, or 500 freehold acres of Mayfair and Belgravia?

The low-born woman who made the Duke of Westminster’s fortune

Today’s article in the Financial Times prompts this historical footnote.

The FT quite rightly highlights the Court of Appeal action of chartered surveyor James Wyatt, of Parthenia Limited, who is challenging the mathematical calculation of values in lease extensions.

If he wins the case, and he is deploying the beguiling tongue of Philip Rainey QC, he will break up a cosy earner for freeholders. They presently earn millions based on flawed calculations drawn up on the back of a fag packet by mainstream chartered surveyors toadying up to London’s powerful freeholders. Allegedly, may need to be placed somewhere in that sentence.

None is more powerful than the Duke of Westminster and, as a matter of pure coincidence, it was his Grosvenor Estate that commissioned the flawed mathematical model for lease valuations back in 1996. This was a detail that did not escape the FT.

It is probably even more of a coincidence that this model, acknowledged to be flawed by the Upper Tribunal of the property chamber, has meant leaseholders have paid millions more than they should have done to extend their leases.

It will doubtless astonish young history students that the Grosvenors do not own large chunks of central London owing to brilliant commercial acumen, but to a lucky inheritance through a modest woman.

(As a matter of fact, almost all English dukedoms owe their origins to the cleverness or hard work of women, who put in fatiguing and largely horizontal labour on behalf of male, often royal benefactors.)

Curiously enough, in Restoration England there were two women in London called Mary Davies, with slightly different spellings.

One was an actress and what today would probably be described as a sex worker. She caught the eye of Charles II and had an expensive portrait painted, before being given the push in favour of Nell Gwynne.

The other was the frumpish and pious new money daughter of a successful scrivener, or scribe, although who knows what course her life may have taken as at the time of her marriage she was only 12.

Her astonishing dowry was the manor of Ebury, 500 acres of land north of the Thames to the west of Westminster.

For her husband to be, the Cheshire baronet Sir Thomas Grosvenor, 500 acres of freehold property, even if a lot of it was a marshy urban rubbish tip, were far more attractive than the diversions of Moll Davis.

In 1677 he married Mary, which would later establish his family as one of the richest in the country – subsequently, the richest – and they were repeatedly promoted through the aristocratic ranks until eventually given a dukedom at the end of the Victorian age.

It was a slow and steady progression, rather than Vincent Tchenguiz’s brief rise and (as yet incomplete) fall with residential freeholds.

Mary’s acres remained largely untouched by the Grosvenors until the 1720s, when they developed the northern part – now known as Mayfair – around Grosvenor Square.

A few generations later, in the 1820s, their focus moved south – to what is now Belgravia – developing Eaton Square, Chester Square and other famous addresses. Later in the 19th century, the area of Pimlico was developed; this was sold in 1953.