Bridge of Hrethgir

The Bridge of Hrethgir was a final attempt to avert the destruction of Corrin when the Vengeance Fleet approached the planet to initiate the Battle of Corrin. It was a space ring of orbiting cargo pods around the planets, occupied by humans.

Role in the Battle
The Independent robot Erasmus concocted the ploy to stop the Army of Humanity from destroying the last Omnius incarnation. All of the almost 3 million humans on Corrin, including traitorous Rekur Van and the clone of Serena Butler, were loaded into cargo pods and deployed in orbit around Corrin, each rigged with explosives that would be triggered by Erasmus as soon as the fleet commander passed the line, giving him pause.

Erasmus's ward, Gilbertus Albans, did not want his "father" to be directly responsible for the massacre. He asked the robot to key the destruct sequences in all the containers to the sensors in their scrambler satellite net. Gilbertus used his programming skills to add receivers to the pods. The constant signals broadcast by the scrambler satellites acted as a trip wire for the self-destruct systems installed. If the satellite signals were disrupted (by the Army of Humanity passing through the net), those sensors would transmit the signal and the self-destruct cycle would activate. This would give their commander an additional reason to hesitate.

Gilbertus Albans disobeyed his father and joined the Serena clone in her pod. Not willing to sacrifice his "son" this way, Erasmus over-rode the kill switch for the Bridge, which spared the humans inside.

The Bridge was also the seed for the eons-long feud between House Atreides and House Harkonnen. Vorian Atreides' second in command, Abulurd Harkonnen, disagreed with pressing the attack because all the humans of the Bridge would be killed. Vorian ordered the attack, feeling that this and future generations of humanity should be free from the Thinking Machines, which would ensure the death of the humans. In response, Abulurd defied his commander and changed the weapon firing keys for all the battleships in the fleet, thus paralyzing the Army of Humanity in its most important battle. Vorian accused Abulurd of cowardice and the feud grew.

The Bridge of Hrethgir was a very important event in Imperial history could be seen among other things on a fresco in the Imperial Palace on Kaitain.

Behind the scenes
The Bridge of Hrethgir is first mentioned in Dune: House Atreides, depicted on a fresco, without any explanation or description. It's possible that the authors envisioned the term to refer to an actual bridge on a location on the planet Corrin (possibly a place called "Hrethgir"), before being retconned.

Appearances

 * Dune: The Battle of Corrin
 * Sisterhood of Dune
 * Mentats of Dune
 * Dune: House Atreides