"The Inheritors" is a 1972 novel by A. Bertram Chandler, set in his shared universe of "The Rim". It was published as an Ace Double, and the other side of the book, "The Gateway to Never", was also written by A. Bertram Chandler, and featured the same character. In fact, this book explains some of the backstory to that book. I have no idea whether either Chandler, or the Ace editors, knew that these books would be bound together while they were being written. There is nothing in the packaging of the Ace Double that tells you what order to read them in. Also, apparently, A Bertram Chandler's stories about "The Rim" were written in a non-linear fashion, with this book taking place 20 years before the events of "The Gateway to Never".

In this book, Chandler's main hero, John Grimes is still an active space navy officer, and has been called to make contact with a "lost world", a planet that was colonized during an earlier period of space exploration, and has since resorted to a more primitive, if comfortable way of life. At the same time as he is sent there on a diplomatic mission, two commercial operators have opened trade missions with the planet: one with good intentions, and one, Drongo Kane, who seems to be intent on enslaving the natives. But Grimes can't prove that space pirate Kane has something nefarious planned. The book then delves into the twin mysteries of what Drongo Kane's plan is, along with why the residents of this planet are so successful at keeping a state of medieval stasis.

This book is another Ace Double where spaceships come into contact with a primitive, or regressed society, which seems to be a common plot device in Ace Doubles. And like the other side of this volume, "The Gateway to Never", A. Bertram Chandler, 60 years old at the time of publishing, seems to be addressing social issues. Grimes has a lieutenant on his ship, name Saul, who is an angry black man. The book pretty much puts it in those terms:

Grimes sighed. He wished, as he had wished before, that Saul would forget the color of his skin "All right, all right--Whitey's to blame for everything"
The use of the term "Whitey" as a derogatory term for white people certainly seems quaint today, and it seems unlikely that it would still be getting bandied about when this book takes place, uncounted thousands of years in the future. Notice, however, although while a sextagenarian Australian might not be able to quite process how to use African-American slang of the 1960s, he is otherwise sympathetic to the sentiments: the book is critical of colonial mindsets and exploitation of indigenous populations.

On top of that, the book also adds an interesting layer of intertextuality. Early on in the book, I noticed references to the works of Cordwainer Smith, especially Norstrilla. I thought that Chandler drawing a few parallels to Smith was perhaps him giving a wink to fellow science-fiction fans, but it turns out that this was an instrumental part of the plot: Cordwainer Smith's books were not just an inspiration to Chandler, but to the characters in the book, who based the civilization of their planet off of his books. So this book, which could seem at first to be standard space opera, manages to have some social commentary and metatexuality rolled up in it!