From an early time the town straddled three parishes - Barnet parish covered the southern parts of the town whilst the north-east fell into Monken Hadley parish and the north-west was in South Mimms parish, both of which were in Middlesex, whereas Barnet was in Hertfordshire.
In 1894 the town was unified when Monken Hadley and South Mimms parishes were both split, creating new parishes called Hadley and South Mimms Urban respectively, which both joined Barnet to become the Barnet Urban District. At the same time, two sections of Barnet parish were made separate parishes: Arkley, covering a rural area to the west of the town, and Barnet Vale, covering the growing suburban area to the east of the town. Arkley's independence was shortlived - it was absorbed into Barnet Urban District in 1905. Barnet Vale was never administered separately - from its creation in 1894 it was part of East Barnet Urban District. Both Barnet and East Barnet Urban Districts were abolished (with all their constituent parishes) in 1965, becoming parts of the London Borough of Barnet along with Finchley, Friern Barnet and Hendon.