Banking system before RBI

How was the financial and banking system in India before RBI came being into being?

Based on what I have learnt and what I can deeuce, there were regional banks created by British who controlled the financial system, viz issuance of currency etc.

And before that, I think that the Muslims tried to centralise the administrative and financial system throught India from Delhi. They were successful in it for the most part.

What financial system existed before Muslims had established rule in Delhi is hard to tell because a lot of history has been erased and eroded and we have gone through change of languages, culture etc, so it becomes hard to relate and ascertain.

I would appreciate what you guys know on this subject matter.