Chapters 7 and 8 were not in chronological order. They happened while Belshazzar was still the king. Chapter 9 now returns to the events of the reign of Darius who became king in chapter 6.
# It was Ahasuerus who had been made king over the realm of the Babylonians
This is background information about who Ahasuerus was. The UDB places this in parentheses to make that clear. (See: [[rc://en/ta/man/translate/writing-background]])
# who had been made king over the realm of the Babylonians
This can be stated in active form. AT: "who became king over the realm of the Babylonians" or "who conquered the Babylonians" (See: [[rc://en/ta/man/translate/figs-activepassive]])