From the Wikipedia page [1]:
Feltham was an urban district in Middlesex, England from 1904 to 1965.
It was based on the parish of Feltham, which had previously been part of the Staines Rural District. In 1930, the Rural District was disbanded, and the parishes of East Bedfont and Hanworth added to Feltham.
It was abolished under the London Government Act 1963, in 1965, to form part of the new London Borough of Hounslow, in Greater London.