The name Belsize Park comes from the 17th-century manor house and parkland (built by Daniel O'Neill for his wife, the Countess of Chesterfield) which once stood on the site.

Rebuilt in 1663, it was sublet by 1721, when the parklands opened as pleasure gardens for those looking to escape the dirt and grime of the City of London, with concerts, singing, dancing and country sports such as fishing and racing.

The wealthy leaseholders soon enabled themselves to purchase the freehold from the church, allowing the accelerated development of Belsize as a Victorian country urban suburb of London.

Victorian development started along the main London to Hampstead road from 1815 through the works of Edward Bliss, a self-made man who had leased and then bought the southeastern-located Newman's House lands, on the west side of Haverstock Hill north of England's Lane.

The opening in 1851 of Hampstead Road railway station on the L&BR prompted William Lund in 1852 to agree a 99-year construction sublease on the former Forsyth estate.

He proposed developments to the west of Haverstock Hill, although his plans were curtailed by construction issues associated with building over both the Pond Street sewer and the L&BR tunnel.

In 1853 he proposed demolition of the main house, with Daniel Tiley taking the lead role in constructing Belsize Square and associated properties.

Mimicking the then fashionable styles of Kensington and Bayswater, between 1851 and the late 1860s he built over 250 8-10 bedroom semi-detached stucco houses with large porticos, aimed at the middle classes.

The church undertook a similar agreement in 1857, reacquiring full control over the portion of Todd's lease north of Belsize Lane in 1865, and again selling it to Tiley.

Due to issues associated with construction over the L&BR tunnels, in 1859 he sold Rosslyn House and its extended formal gardens to Charles Henry Lardner Woodd.

Willett redeveloped much of the former Eton College estate with newer, smaller but still substantial properties inspired by Queen Anne style architecture.

The area on Haverstock Hill north of Belsize Park Underground station up to Hampstead Town Hall and including part of a primary school near the Royal Free Hospital was heavily bombed.

The lyrics of the international chart hit "Kayleigh" by rock band Marillion in 1985 include the line "loving on the floor in Belsize Park".

[4] The Camden Town Group artist Robert Polhill Bevan and his wife Stanislawa de Karlowska lived at 14 Adamson Road from 1900 to 1925.

Belsize Park is mentioned in the Hitchcock thriller, Dial M for Murder (1954) by the lead character Tony Wallace played by Ray Milland when coercing his accomplice, C.A.