One of the most overlooked, in my opinion, aspects of the Klingon Empire is that they have subjugated species under them. The fact that this is almost never shown is puzzling to me. The Empire must be pretty large, and it must comprise dozens of subjugated species (just like The Romulan Empire must have), and yet, these species never play a part. I hope this will change in this series, since Klingons seems to be explored so in depth!