Warley was entirely new, formed by the merger of the county borough of Smethwick with Oldbury and Rowley Regis, whilst the other districts and boroughs were partitioned variously between the existing county boroughs. Solihull had been newly promoted to be a county borough in 1964, whilst Birmingham, already by far the largest county borough in the country, did not expand any further at this stage. A single West Midlands Constabulary was formed for the Black Country county boroughs, whilst Birmingham retained its Birmingham City Police and Solihull continued being policed by Warwickshire Constabulary. On 1 October 1969, West Midlands Passenger Transport Authority was established, which covered the county boroughs, the urban districts bordering these, as well as Cannock, Redditch and some surrounding rural districts.