Re: "Scrambled case" in other writing systems?

I've often wondered, how did the two case system get started? What
was the original problem that lowercase letters were devised for (I
assume upper came first)? And when? I expect that the original
premise has been lost to the ages, I'd be grateful if anyone could
share the leading theory here.

Was there ever a period where other cases (beyond two) were created
but then died off as a failed branch in the evolutionary tree?