Manufacturers Time Line

Many British manufacturers started production and were successful, only to hit hard times later on. Especially during the depression and war years. This resulted in the buy-outs and mergers to for bigger, but fewer manufacturers, although often the marque would continue under another manufacturer. Interestingly, it is quite often the older company that is absorbed into the newer company.

I have tried to put together a picture, and while not totally comprehensive it covers the main British marques. Many manufacturers were established before starting motorcycle manufacture later, and I have tried to show the date they started and finished motorcycle production.

Additional Information by Mike Jackson:

CALTHORPE

Shown as ceasing production in 1938 and eventually going to DMW, who started in 1947. 
I think Calthorpe was actually sold to one of the Douglas family from Bristol in 1938. 
In his book Villiers Singles & Twins Roy Bacon mentions a prototype Calthorpe being made by DMW in 1947, 
but does not say whether this was produced for whoever owned the right to the name or whether the name was actually owned by DMW themselves at the time.

NEW IMPERIAL

Shown as going to BSA in 1939. In fact the Company was bought by J. Sangster in 1938 and the name was sold to BSA by Sangster in 1944 when he also sold them the Ariel Company.

SILK

Although some early Silks had Scott engines the respective Companies were never joined, so the Silk should really be regarded as a machine in its own right.