He was born William John Cavendish-Scott-Bentinck (Lord John Bentinck) in London in 1800. His family had him educated at home, and on turning 18, he became an ensign (banner bearer) in the army, progressing to rank of captain.
He became an MP (styled Marquess of Titchfield) in 1824 for two years before surrendering his seat to his uncle due to ill health - his Wikipedia article suggests he suffered from "lethargy due to delicate health" in the army.
From 1824 to 1834 he held a sinecure army position (paid for doing nothing) as the regiment had disbanded.
As for his private life, The History of Parliament Online says "Titchfield travelled extensively on the continent, where he indulged his passion for opera." He died childless and unmarried - "the opera singer Adelaide Kemble, to whom he was devoted, had rejected him as a suitor".
In 1854 he succeeded his brother and inherited the seat of the Duke of Portland at Welbeck Abbey. This gave him a seat in the House of Lords, though it seems he rarely attended nor took an active interest in politics.
Duke of Portland coat of arms
What did occupy his time was sophisticated building projects like a towered stables (the Nottingham Post reports the family had amassed £30m in today's money in horse winnings by the 1880s), a Gothic village, almshouses, tens of beautiful stone lodges surrounding the estate, vast kitchen gardens with recesses for braziers for ripening fruit, follies like grottos and summer houses and a skating rink.
One of 50 lodges
Almshouses
A tunnel portal
The Welbeck estate covers one of the four former dukal estates in North Nottinghamshire (others being Clumber Park, Thoresby Hall and Worksop Manor), part of Sherwood Forest known as the Dukeries, a land full of woods, streams, lakes, meadows and parkland.
Monument of the 4th Duke (his brother) erected by the 6th (his cousin)
It's the most seismically active area in the British Isles, blamed on mining at the nearby now closed Thoresby Colliery.
On the estate is a garden centre and rustic supermarket on the site of the kitchen gardens, the Harley Gallery (which used to be the gasworks, built in 1860 to provide light) housing the Portland Collection of 'internationally important' art and a stables and riding school and a village.
Riding school
Stables
The section is 900 yards long - turning off the torch gives full darkness:
Skylight seems to have kept its original glass
Not all are underground - here the roof seems to have collapsed, nature taking over.
Underground rooms included a 2000 capacity ballroom with a painting on the ceiling of a giant sunset, a billiard room, an observatory, libraries, this grotto area:
Large spaces to live and entertainment, yet apparently visitors were banned. Furniture was stripped out of the house and all the walls were painted pink. A toilet was installed in each of the empty rooms.
Wikipedia paints the Duke as a recluse and an eccentric, travelling underground where possible, mainly at night, a lady servant walking 40 yards in front with a lantern.
This one starts in a field and emerges in another after bypassing a lodge.
He employed up to 15,000 workers and though treated well (given a donkey to share and an umbrella on their start) were not allowed to address him. Real life contact was largely with his valet - correspondence including with his wide ranging family and friend network was done by letter.
...even with his hidden roads, the Fifth Duke was not content. From time to time he found it necessary to go to London. He would enter his carriage, a “dismal hearse-like vehicle,” we are told, and be driven from his home along the underground road to where it emerged into the open at the frontier of his estate. So that no one could see him, the curtains of the carriage were always drawn, the carriage itself being drawn by six ponies driven by “lads” from the stables. At Worksop railway station, the Duke’s carriage was hoisted on to a railway truck, but where he went to or what he did in London is a mystery that has died with him. (Look & Learn)An illustration of how it might have looked as a carriage came through:
This goes towards Worksop (blocked off).
The Shady Old Lady's Guide to London tells us about his occupancy at Harcourt House, his residence in the capital:
During the occupancy of the eccentric fifth Duke, William John Cavendish Bentinck Scott, he enclosed the garden with a gigantic screen of ground-glass, extending for 200 feet on each side and 80 feet high. His object in having this screen constructed was to prevent the residents of neighbouring Henrietta and Wigmore Street from viewing the garden.Mick Jackson's Booker shortlisted 1997 The Underground Man imagines his last years. Also Tunnel Vision: The Enigmatic Fifth Duke of Portland by Derek Adlam must be read.
Speculating the reasons behind such designs, Look and Learn says:
It has been suggested that the Fifth Duke led a “Jekyll-and-Hyde” life, and that while he was thought to be hidden in his underground country home, he was, in fact, leading an entirely different existence in London. If this were so, it has never been proved. But what does seem certain is that the Duke suffered from a disfiguring skin-disease – maybe a complaint in which daylight affected the skin – and for this reason alone he led his lonely underground life.
