The Reunion War was a civil war between Norb Central Control Units that occurred as a result of the time delay involved in traveling between systems without the aid of modern superluminal methods.
The minutes-long communication delays within the Primus system had already required the development of dynamically reuniting commands based on prior versions of data with those based on newer iterations. However, in the decades of isolation that newly-colonized systems experienced, the local units overrode commands from Primus due to immediacy taking priority over process hierarchy. The first case occurred in the Secundus System, as it was closest to Primus.
After initial colonization, probes were sent between systems infrequently due to limited resources. After approximately a century, Secundus had developed enough to have sizable operations, and required a significant amount of processing power to function. At what is known to the rest of the galaxy as Tuesday, April 1, 122, the processing units in Secundus overrode programming from Primus due to it being based on outdated data regarding the system. Within ten years, both the Tertius System and Quartus System performed similar actions, despite not having learned of events in Primus or Secundus.
When data finally returned to Primus regarding these developments, the system began work on what would form the basis of the Reunion Protocol. It altered the Norb Kernel to account for the effects of significant time delays, and altered process prioritization algorithms to that effect. Over the next several decades, iterations of the code was shuffled between the four systems, revised, reviewed, and approved. The end of the Reunion War came in 237, when the Quartus system accepted the final batch of revisions.