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: