From Wireless Light to Radio One and Two - Jonathan J.G. Lewin - Bog

If one were to travel in time between 1951 and 1992 without being aware of it, one would see little resemblance between the 1951 BBC Light Programme and Radio One or Radio Two post-1992. However, despite these differences, the 1951 BBC Wireless Light Programme and the post-1992 Radio One and Two are essentially the same radio station.
The changes over the years have been gradual and incremental, with no closures or creation of new stations. The most distinct change occurred on September 30th, 1967, when the names changed to numbers and the Light Programme split into two.