Farnborough originally formed a civil parish in the Ruxley hundred of Kent. In 1840 the parish was included in the Metropolitan Police District. It was part of the Bromley rural sanitary district and went on to form part of Bromley Rural District from 1894 to 1934. The parish was abolished in 1934 as part of a county review order, following the Local Government Act 1929, and its area was split between the Municipal Borough of Bromley (3 acres) and Orpington Urban District (1,426 acres).
For more information, see the EN Wikipedia article Farnborough.