Lord Mahon's address on Harley Street: Number 52, now Number 61

Fig. 1: The 1778 Rate Book for Harley Street, showing Number 52: The address of Lord Viscount Mahon

On a recent research trip to Westminster City Archives, I had a look at the Rate Books for Harley Street for the year 1778. I chose that year as it was the period in which William Pitt the Younger was regularly staying with the Mahons on Harley Street. Lord Mahon, later Charles, the third Earl of Stanhope, had married Pitt's sister Lady Hester in December 1774, and the Mahons had a house on Harley Street. This was the exact same property in which their first child Lady Hester Stanhope was born in March 1776.  The property on Harley Street was also where Pitt stayed during the period in which he was arranging and serving as chief mourner at his father William Pitt the Elder's funeral. The exact number of this property has never, to my knowledge, been mentioned in any biographies of Pitt, Charles Stanhope, or Lady Hester Stanhope, so it is a real gem for the 18th century historian interested in tracking down Pitt's exact movements at various periods in time. 

From the image above, we can see that Lord Viscount Mahon was living at number 52 Harley Street, and paying £140 in rent in addition to the costs of repairs, additional rates, and a watch rate. 

Fig. 2: Lord Mahon's residence at 52 Harley Street, from Horwood's 1799 London map

The Mahons lived three houses up from the junction where Harley Street meets Mary Le Bone Street and New Cavendish Street (now both streets are simply called Cavendish Street). William would occasionally sign off his letters to his mother, Lady Chatham, with "Harley Street, Cavendish Square" when he was staying at his brother in-law and sister's house. In fact, the part of Harley Street where the Mahons resided was several street crossings away from Cavendish Square. Captain Alexander Hood lived at 7 Harley Street, which was much closer to the square. As I mentioned in a previous post, Hood was instrumental in getting the naval career of Pitt's youngest sibling, James Charles Pitt, up and running. Lady Harriot Pitt had also stayed at the Mahon's residence, and spent time with the Hoods in the spring of 1776 when she was in London. Thus, in various capacities, Harley Street was well-known to members of the Pitt family. 

Since the late 18th century, 52 Harley Street has become number 61, and the building itself has undergone extensive changes. The house pictured on the right is number 61 (formerly number 52). The house on the left still largely retains its Georgian exterior, and is shown here to give you an idea of how the Mahon's residence must have once appeared.

Fig. 3: A modern-day view of number 61 (formerly number 52) Harley Street

I wonder if the Chevening Estate is aware that Charles, third Earl Stanhope, lived at this address in the 1770s? Lady Hester Stanhope was also born there on March 12, 1776. Despite its significant external changes, the property still retains an historical significance.

Image Credits:

Figure 1: The 1778 Rate Book entry for Harley Street, showing number 52: The house of Lord Viscount Mahon. Westminster City Archives, London.

Figure 2: Lord Mahon's residence at Harley Street, from Horwood's 1799 London map.

Figure 3: A modern-day view of number 61 (formerly number 52) Harley Street (image from Google street view).