The war started out in 2114 with a Terran occupation of Procyon. As the Vilani have a world at Nusku, the Terrans went to the galactic east. The landings were without any opposition and administrative in nature. The 5th Rifles Division settled down for occupation duty. Then an Imperial Task Force arrived in system having used a tanker in the Sirius System to pass through that tertiary star. Later intelligence would reveal that the Imperials appealed to the Emperor for additional funding in an effort to quickly end Terra’s expansionist plans. The invading Vilani quickly destroyed the Terran fleet in system, including two valuable transports, and landed two regular troop divisions and another of Jump Troops. The 5th Rifles put up a valiant fight but was overwhelmed by the Imperial ground forces and surrendered. By the end of 2115, the situation looked bleak for the Terrans seeing as they were being hemmed in by the Vilani.
The defeat at Procyon, coupled with the presence of Vilani at Nusku, led to a unification of effort in the Terran forces. Production of Missile Boats was begun, as well as raising defensive forces. The new Terran Confederation was readying for a defensive war of the homeworlds. That is until the Imperials overstretched themselves.
Intelligence agencies disagree if it was just poor planning or hubris that led to the Imperial invasion of Midway. The planet had no Terran outpost or other forces in system. Maybe the Imperials thought they could seize a forward staging area. Regardless, the Terran Fleet put an end to those plans by pulling together a scratch force and ended the Imperial eastern invasion threat. First, they defeated the Imperial Task Force above Midway, leaving two divisions of Imperial troops stranded on the planets surface. Additionally, a Scout squadron passed through the Procyon system (bypassing a lone Imperial Transport squadron) and jumped to Sirius. There the scouts engaged the Imperial tanker squadron in the system and destroyed it before it could escape. Though a one-way mission (the scout squadron had no way to get home) by controlling the Sirius system, even for just a short time, the Terrans isolated the eastern invasion fleets. Left stranded in Procyon and beyond were two Imperial transport squadrons and three divisions of troops, including the 60th Proxima Centauri Jump Division. By the end of 2117 the transports had been run down and eliminated.
The Vilani Provincial Governor was shocked. In four years of combat on the trailing side of Terran space, the Imperials had lost 2xCL, 4xDD, 2xSC, 3xTR, a tanker, and had three divisions of troops trapped behind enemy lines. Looking over his ledger, the governor was aghast at the 27 RU of losses – as much as the province produced in two years. Production was quickly reorganized with additional transports being built and more troops raised. Acting on intelligence reports the Terrans were building new missile boat attrition units, the governor approved the Navy request to build a carrier with fighters. The Navy also adopted a forward defense posture for Nusku and the spinward side of Terra, gambling the Terrans did not have a tanker in production that would allow them passage through Sirius just yet.