A correction: It was not called Network Three. The proper title in 1966 was the BBC Third Programme. The name was changed to BBC Radio 3 in the 1970's. The original name came from the fact that the first BBC station was called The BBC Home Service, and the second was called The BBC Light Programme. Naturally the next was called the Third Programme. The BBC World Service has been for international broadcasting, and it keeps that name to this day. The Home Service is now called BBC Radio 4 and the Light Programme is called BBC Radio 2. Radio 1 was added when the names were changed, and is for the latest popular music.
A correction: It was not called Network Three. The proper title in 1966 was the BBC Third Programme. The name was changed to BBC Radio 3 in the 1970's.
The original name came from the fact that the first BBC station was called The BBC Home Service, and the second was called The BBC Light Programme. Naturally the next was called the Third Programme. The BBC World Service has been for international broadcasting, and it keeps that name to this day. The Home Service is now called BBC Radio 4 and the Light Programme is called BBC Radio 2. Radio 1 was added when the names were changed, and is for the latest popular music.
genome.ch.bbc.co.uk/1856317b12460495d8a62c29092b2d35