Looking for good recommendations on books to learn more about Jewish communities in Babylonia before and during the Tannaitic period

Basically the title.

From what I understand, there is not much one can say conclusively, by the standard of modern history, primarily due to the lack of written sources. This is very mysterious to me. Their existence was recorded, and their settlements were close to the trade routes. Even if there was a language/cultural barrier(at all), it wouldn’t be as big as that between the Judeans and Greco-Roman diaspora, right?

So, I am basically asking for two things:

1. Explanations for the “dark age” of the literature in Babylonia
2. Reputable history works on that period

Note: I am not asking about religious texts. I am open to anything that is related(broadly interpreted) to the Jewish communities in Babylonia in this period.