Following Edward Harley’s marriage to Henrietta Cavendish, a wealthy Marylebone heiress, the couple planned to develop some of their land (the ‘Cavendish–Harley estate’) for residential use. They started to build in their new Cavendish Square and proposed heading north.
The Duke of Chandos had also been an owner in the Marylebone area in the early 18th century. This became part of the Cavendish-Harley estate through the marriage.
Around 1716, a street called Chandos Street was begun. Nearby, a street called Harley Street was also started.
Edward Harley died in 1719. The following year – 1720 – his widow was caught up in the South Sea Bubble* and the financial waters chilled for many builders.
In 1726, it was decided to swap the names – Harley Street became Chandos Street and Chandos Street was called Harley Street.
Harley Street (the former Chandos Street) remained a stump leading north off Cavendish Square for the next thirty years.
The Chandos-Harley estate was in the 1720s temporarily financially in deep trouble. With his family’s connection to Marylebone, the Duke of Chandos leased land from the estate – he had had a great idea. In 1725, a reservoir known as Marylebone Basin (‘Bason’ on Rocque’s map) was excavated.
A number of reservoirs and ponds took advantage of the fresh water springs rising through the gravel at points all along the southern fields of Marylebone parish. The largest such project was the Marylebone Basin. Pipes were proposed to supply St James’s Square from this new body of water but the City of London commissioned the New River Company to quickly lay other pipes to Cavendish Square, scuppering the Duke’s plan.
The plan needed to refocus.
For a brief period, the area surrounding the Basin’s southern end had a distinct character. This character was more in keeping with Marylebone’s reputation as a sometimes unruly destination for leisure and entertainment, rather than the orderly residential streets that would later define the area.
Immediately north of the short stumpy version of Harley Street a new inn called The Blue Posts was built in 1719. Harley Street could not continue in either direction since the Blue Posts was in its way. Eventually the inn was demolished to make way for the road.
A pair of small houses was built in 1723 next to the Blue Posts. A bath house – marked Cold Bath on the Rocque map – came next on the site of 29 Harley Street, fed by the City of London’s conduit.
Behind The Blue Posts, there was an existing inn called the Half Way House opposite a track which led to Marylebone village and conveniently now right beside the new reservoir.
But Marylebone Basin’s repurposing as a leisure destination was not a financial success. In 1749 Chandos’s son sold all the land north of the current Queen Anne Street back to the estate for £250.
The Cavendish-Harley estate had passed to Henrietta and Edward’s only child, Margaret Cavendish-Harley. In 1734, Margaret married William Bentinck, 2nd Duke of Portland. As development continued, the area became known as the Portland Estate, passing through subsequent Dukes.
When the 5th Duke of Portland died childless in 1879, his estates were divided between his sisters and his cousin, who became the sixth Duke. The London estate was initially shared by two elderly sisters, but from 1889 was held solely by Lucy, the last surviving sister and widow of the 6th Lord Howard de Walden.
Upon Lucy’s death in 1899, the Marylebone estate was inherited by her eldest son, Frederick. Since then, it has been known as The Howard de Walden Estate.
Fortunately for the estate – whatever it was called – things began to pick up again in the 1750s.
In 1755, prominent residents of Marylebone, Paddington and Islington – then all separate villages – sought parliamentary approval for a turnpike trust road. This route would skirt London’s northern built-up areas, primarily serving as a drovers’ road for cattle and sheep bound for Smithfield’s live meat market. It aimed to alleviate congestion on the existing east-west route via Oxford Street and High Holborn.
The proposed road would run eastward from near the Harrow and Edgware Roads junction, past Marylebone Lane’s northern end to Tottenham Court, then via Battle Bridge and St Pancras to upper St John’s Street in Islington, close to the market. A parliamentary committee endorsed the plan, suggesting management be split between two existing trusts: St Marylebone and Islington.
The Highgate and Hampstead Roads Act received royal assent on 27 May 1756. It stipulated a minimum road width of 40 feet, with no buildings permitted within 50 feet of its edge – a common requirement for drovers’ roads. Construction began swiftly, with the road built to at least 60 feet wide, initially involving basic hedge removal and ditch filling, bordered by fence posts. Handily, the new road doubled up as a military London bypass in those times of threatened Jacobite rebellions and royal nervousness.
Once complete, the New Road (now Marylebone Road and Euston Road) provided a new boundary for London’s expansion – a prototype green belt.
Each trust initially kept tolls from travellers passing its gates, though tickets were valid across both sections. The St Marylebone trust collected £400 in 1757, increasing to £700 by 1764. (St) Marylebone was becoming rich.
What was the Chandos-Harley estate – by then called the Portland Estate – looked at the new opportunity and began a massive building programme. Cleverly the estate held onto the freeholds for each plot.
The site of the Marylebone Basin was developed in 1768 as Mansfield Street. Marylebone Gardens were built over in 1778. A whole grid of streets filled the area.
Harley Street was largely built up after 1750. The two blocks between Weymouth Street and Marylebone Road was originally called Upper Harley Street until 1866 when the whole street was combined and renumbered.
In exchange for other land, The Crown gave its land on the west side of Upper Harley Street to the Portland Estate, but kept land on the east side to build Nash’s Park Crescent. The street north of Devonshire Street was at first to be called Ulster Street and to cross over the New Road into the park, but in the event the Harley Street name prevailed.
Harley Street’s modest townhouses became popular among middle-class residents, including scientists, military personnel and politicians. The Duke of Wellington was at 11 Harley Street, on the future site of no. 34, in the early 1800s.
By 1830, Harley Street boasted 145 residences and a single public house, The Turk’s Head. A decade later, of all the houses, 37 had ties to the East India Company, whilst 13 were linked to slave ownership. At this time, Harley Street was also home to twenty Members of Parliament.
Medical professionals began settling in Harley Street in the mid-1800s. Many local brand new streets offered affordability and central location for professionals. Harley Street was no nearer than other streets to local hospitals.
But somebody moved in, causing others to move in.
The Georgian townhouses on Harley Street were well-suited for conversion into medical practices, with ground floors for consultations and upper floors for medical professionals to live above with their families.
By 1860, twenty doctors had established themselves on the street, with this number increasing tenfold by the First World War’s outbreak.
Notable Harley Street residents included Florence Nightingale, founder of modern nursing; Joseph Lister, who made crucial advances in antiseptic surgery; and Lionel Logue, speech therapist to King George VI, who helped the future monarch manage his stammer.
Cavendish Square was the heart of the upper-class section of Marylebone – the further south on Harley Street and thus nearer to the square, the better the medical address.
After the Second World War, psychological counselling and cosmetic treatments became available in the street. The National Health Service’s creation in 1948 led to gradual growth in medical practices, eventually reaching 1500 clinics in the area.
Currently, over 3000 medical innovators operate in and around Harley Street’s expanding medical zone.
Since they still own most of the freeholds, the Howard De Walden Estate (a.k.a. Portland Estate, a.k.a. the Cavendish-Harley Estate) oversees the area, ensuring all private clinics maintain exemplary medical standards for their patients.
