The Union-Oroso Conflict (sometimes mistakenly referred to as the Human-Oroso War) occurred at the height of the Third Age. European colonists had been held back in their expansion due to the strains of the Pan-Eurasian War and had subsequently missed out on prime ‘local’ colony worlds to their American and British rivals. They had to explore further afield to find suitable worlds and this brought them into conflict with the usually peaceful Oroso Conclave. Union colonists were well-armed, if foolhardy, and were quick to skirmish with local Oroso populations and their protectors. Outmatched by the aliens, the gun-toting civilians were quick to call on their military to help.
The Union military was being rebuilt following the damaging, inconclusive war with the Asian Coalition and eager to test new recruits, tactics and toys. However the new additions were in the minority and it was with predominantly old equipment that they squared up to the Oroso.
European Admirals highlighted several Oroso military and civilian targets and assigned task forces to siege and capture them. The Pan-Eurasian War, however, led to a specific set of heavy handed tactics that would prove ill-suited against a patient, defensively-minded foe like the Oroso. The EUN found themselves evenly matched or overpowered; most of them retreated with severe damage or losses. In particular, their ageing fightercraft were outmatched by the Oroso T’frr and – with no fighter cover – the Union heavy ships were particularly vulnerable.
The Oroso retaliated with punitive strikes against these retreating forces, managing to rout a force of heavy destroyers at the Battle of New Dresden. The Union admiralty demanded reinforcement from the Core and it was only the arrival of the brand-new Caracals of Grendel Squadron which turned the tide at the decisive Battle of New Riga. Finally given a bloody nose, the Oroso forces withdrew and the conflict was soon ended with an armistice.