Orpington Urban District

From the Wikipedia page

Orpington was a local government district in north west Kent from 1934 to 1965 around the town of Orpington.

It was created an urban district in 1934 from parts of the abolished districts of Bromley Rural District and Chislehurst Urban District, taking in the entirety of Chelsfield, Cudham, and Knockholt parishes, and most of Farnborough, part of Keston, most of Orpington, most of St Mary Cray, part of St Paul's Cray and part of West Wickham.

In 1965 it was abolished by the London Government Act 1963 and its former area transferred to Greater London from Kent. Its former area was combined with that of other districts to form the present-day London Borough of Bromley.