Northwick Park, a Metro-land suburb

On 2 August 1880 the Metropolitan Railway was extended from Willesden Green via Wembley to Harrow (the station Harrow on the Hill). En route is passed through the Kenton area east of the old town of Harrow. A new station opened on this line on 28 June 1923. It was named Northwick Park and Kenton. In 1937 the station was renamed Northwick Park to better distinguish it from Kenton station (built 1912) on the Bakerloo line. The coming of the railways was soon followed by suburban development, most of Kenton being built between the Wars.

The Kenton area was in the Manor of Harrow, which from 1630 had been owned by the Rushout family, who acquired the Barony of Northwick in 1797. Up until the 20th century much of the land remained in agricultural use. In 1905 Harrow school bought 192 acres of Sheepcote Farm to thwart plans for devel­opment near the school and the fields were converted into a golf course that opened two years later. The rest of the farm - mostly located north of the Metropolitan Railway - was laid out with streets between 1912 and 1914 by the estab­lished owners of the land, the Churchill-​​Rushout family.

The opening of the new station on the Bakerloo line (a contraction of the original name Baker Street & Waterloo Railway) in 1912, provided a strong incentive to develop the area near the station for suburban housing. In that same year following the death of his grandmother, widow of the 3rd Lord Northwick, Captain Edward George Spencer-Churchill (1876-1964) inherited the Kenton estate. Spencer-Churchill's aim was to develop his Northwick Park estate as high class residences with a tennis and social club as the focal point. The housing estate was named after Northwick Park, the family estate in Worcestershire. Captain Spencer-Churchill put up his land for development prior to WWI but the estate was not built until the 1920s and was less ambitious than the original plans.

The Northwick Park Estate is laid out in a formal manner, with the Northwick Circle at its centre. The rest of the streets are laid out along a skewed grid. The street plan includes a number of closes which places the formal layout within the Garden City movement. That esthetic is also noticeable in the buildings. The later extension north of Kenton Road was built by the same building firm and comprises of identical buildings.

Housing was not built until after the opening of the station on the Metropolitan Line in 1923. Captain Spencer-Churchill’s original intention was to create “a unique specimen of town planning, the largest and best laid out estate near London” but the end result was more prosaic. The Northwick Park Estate was laid out as a geometric pattern of streets radiating from Northwick Circle, in the centre of which The Palaestra was built in 1923, forming the focal point and the estate's social and sports centre. The suburban estate of mock-Tudor houses was predominantly built by F & C Costin*, and many of the road names were taken from villages close to Spencer Churchill’s country seats at Northwick Park, Blockley and Gloucester.

* F. & C. Costin was a local building company that built much of Kenton between the wars. Thomas Francis Nash owned other building companies which from the 1920s onward built numerous private housing estates in Kenton, Ruislip and other parts of Metro-land in Middlesex. Local estate agents still use the terms Costin-built and Nash-built to describe properties built by these firms in Kenton.