From the Wikipedia page 
Hendon was a rural district in Middlesex, England from 1894 to 1934.
The rural district was established in 1894 under the Local Government Act 1894, consisting of the following parishes:
- Little Stanmore
- Great Stanmore
- Harrow Weald
The parish of Hendon became an urban district in the same act.
By the 1930s it had become increasingly urbanised, and under the review caused by the Local Government Act 1929, was abolished. It went to form the Harrow Urban District, with the parish of Edgware having become part of the Municipal Borough of Hendon in 1931/1932.
See also Harrow Urban District