In haste en route to Christmas Eve party. Will extend this post later. Poul Anderson fans, please correct me when I get something wrong. I have spotted one definite error...
The error is that Hopewell was mentioned in "A Sun Invisible" and in Mirkheim. It must be difficult to appreciate all of the interconnections in Poul Anderson's History of Technic Civilization on a single reading. I notice many of the internal cross-references because I continually reread and blog about the series.
For example, Vixenite colonists, like Donarrians and Ymirites, feature in the Imperial period of the History and therefore are appropriately referenced in Mirkheim which was written later although set earlier.
The Seven In Space (see here)
Abdallah Enterprises guards its centrum on Hopewell with a single orbiting corvette which is unexpectedly attacked by the Hermetian destroyer, North Atlantis. Because the approaching destroyer beams a warning, the corvette replies with missiles and an energy beam. The Hermetian dodges, disintegrates the pursuing torpedoes, then counterattacks, with an energy weapon and pursues the fleeing corvette while destroying or diverting missiles and absorbing cannon shots, until the survivors surrender.
Meanwhile, Muddlin' Through enters atmosphere with Falkayn broadcasting that the Free Hermetian Navy is about to destroy the installations of a company that has conspired with the Baburites. With Falkayn steering and van Rijn manning the weapons control turret, Muddlin' Through destroys a swarm of defense aircraft, lets staff evacuate the centrum, then destroys it with a fifty kiloton torpedo. Centrum becomes crater.
Again the theme of the novel: looking down at the centrum's "...splendid towers..." before destroying them, Falkayn thinks:
"This was a grand era in its way. I too will miss it."
-Poul Anderson, Rise Of The Terran Empire (New York, 2011), p. 266.