The area began to be developed in the industrial revolution. Northampton Square itself was laid out in 183-4 and building work on the houses began in 1805 from which Nos 22–25 survive. It took its name from the local landowner, the Marquess of Northampton. The layout of the square resulted in some odd-shaped plots at the junctions. The wedge-shaped building that is now No. 18 was built as the Ashby Castle, and remained a public house until c. 1882
The square’s garden was laid out as a large oval with mature London plane trees. To start with this was a private garden for the benefit of the square’s lessees, but it was given to the public in the wake of the investigations of the Royal Commission on the Housing of the Working Classes, at the suggestion of a Captain Thompson. It opened in July 1885, under the management of the Metropolitan Public Gardens Association, with a new layout, designed by the association’s landscape gardener Miss F. Wilkinson. This and other improvements, including a central fountain, a drinking fountain and iron flower urns and were paid for by Charles Clement Walker, a Clerkenwell-born Shropshire JP. Lady Margaret Georgiana Graham, daughter of William Compton the 4th Marquess of Northampton, opened the restored gardens on 8 July 1885. The urns and drinking fountain survive, but the central fountain was replaced by a large public shelter in 1930, erected by Finsbury Borough Council as a bandstand, to designs by the borough engineer, A. V. Cole. Once largely glazed, the shelter is now open to the elements. It is unusual in being a bandstand in a residential square rather than a large public park. In August 2008, it was the inaugural venue for the musical entertainment Big Summer Busk. In 2010, it was a venue for the Bandstand Busking event. After a major refurbishment, the bandstand was reopened in 2011 by the Mayor of Islington and the Vice-Chancellor of the University.
Finsbury put up a store building on the square’s west side in 1937; this was adapted for occasional use as a refreshment kiosk in 2006.
By the 1830s Northampton Square was attracting entrepreneurs and businessmen, but it was probably not an address where the more ambitious lingered. However, an inventor, George Baxter (1804–67), held No. 11 from 1844, by which time he had achieved fame for the development of a patented colour-printing process. He took on No. 12 as well in 1851, but moved away in 1860 when he stopped printing and was heading for bankruptcy. In 1928 Finsbury Borough Council put up a plaque on No. 11 to commemorate Baxter’s occupancy. Following redevelopment of the north side of the square, a simpler plaque was mounted on the site, on the face of the City University.
The square has historically housed clockmakers, jewellers, silversmiths and other fine crafts and craftsmen in these trades lasted until WW 11, but this domestic industry has left little physical trace. The first resident of the square, at No. 1, was Stephen Warwick, seal-maker and jeweller, who stayed until the 1850s.
In 1878, Walter Thornbury reported that No. 35, Northampton Square was the home of the British Horological, (the study of time), Institute, “for the cultivation of the science of horology, and its kindred arts and manufactures”. By the 1960s such trades had left the area and the buildings were a mixture of flats and offices.
By 1901 well over half the houses in Northampton Square were in divided occupation—though as many lower storeys were given over to workshop use the number of inhabitants was not significantly greater than in 1841.
Watchmakers, silversmiths and jewellers all still lived on the square in 1949, but they had all gone by the late 1960s, by when it was largely divided between offices and flats. The older buildings of Northampton Square are nearly all now residential, mostly as houses, though some continue to be divided as flats. In 2005 an application for permission to divide No. 27 was refused on appeal. The square was designated a Conservation Area in 1990.
In 1891, the Northampton Institute was founded, and its original building opened in the Square in 1896. In 2001, a fire gutted the Grade II listed College Building; it was fully restored, re-opening in July 2006. The Institute evolved to become The City University, created by Royal Charter in 1966 and housed in a major new campus, designed by Richard Sheppard Robson and Partners in 1962, and completed in 1976, dominating the north side of Northampton Square. The Ewan McGregor film Incendiary was filmed partly at this location.
Wikipedia and British History Online. / Northampton Square, Clerkenwell EC1