This was the first Poul Anderson book I managed to finish (I got bogged down in one of his later novels a few years ago). The Rebel Worlds is part of a series of books by Anderson about his main character Dominic Flandry and the failing Terran Empire. The series includes Ensign Flandry (1966), A Circus of Hells (1970), etc.
The paradigm of collapsing civilization, decentralization, corruption, despair, rebellion, is by far my favorite sci-fi premise. Space Opera thrives off this sprawling format. What makes the character Dominic Flandry so appealing (at least to me) was that he is perfectly aware of the state of the failing empire yet remains an servant of the Empire. The hero is content to remain loyal to the Empire which is an usual position in sci-fi.
Although I had not read the previous books in the series Anderson gives ample descriptions of his character for first time readers.
(brief plot summary – no spoilers) The story takes place in the last days of the Terran Empire. Barbarians (hark, Ancient Rome analogies proliferate!) threaten the borders of the Empire. ex-Admiral McCormac forced into rebellion gathers discontents (he even employs Barbarians to help his cause!). McCormac’s ravishing wive, Kathryn, is rescued by Flandry from a corrupt governor. Flandry falls in love (of course). The eventual result of the love triangle is a MAJOR spoiler so I will stop here.
Along the way we learn about a particularly fascinating jungle planet and its unique alien inhabitants (comprised of three distinct live forms that gather together to become sentient). Anderson does dwell on descriptions but I did not find that it distracted much from the plot. My main complaint comes from the fact that Anderson skips over MAJOR action sequences. For example, very early in the story Flandry rescues Kathryn and an ingenious plan is hinted at but Anderson never tells us how she was rescued. A nice chapter could have been devoted to this sequence. Perhaps Anderson was working under a stringent page number limit.
Overall, this is fun (albeit semi-empty) Space Opera. The paradigm of decaying empire always holds my attention. Take a peek.