Lenehen, only having a small standing army, was quick to ally itself with other nations in the ACSN for want of allies and soldiers to fight with. Although it could rely on the willpower of its soldiers and support of its people, Lenehen was still dwarfed by the Babylonian juggernaut in many ways. Emperor Xavier's recent arms build-up meant that his army was over three times the size of Lenehen's, and growing every day whilst its industry was swelling with the recent increase in the demand for weapons and munitions. The first to side with Lenehen was an old ally, the Emperor of Panzermee who was quick to offer the support of his sprawling land army which, although lightly armed and supplied, could be a force to be reckoned with- especially when supplied with Lenehenese technology and munitions. Other smaller nations such as Bankampar, Kellonia and Shallum followed his example, realising the extent of the threat that an unopposed New Babylonia posed to the security of their nations. Lenehen's original plan was to contain the Babylonian attackers through use of its navy, but that idea was quickly defeated when the enemy advance forces infiltrated the bay of Thridia by hiding its soldiers and heavy tanks inside civilian shipping freighters. Knowing that nobody would bat an eye at several ships unloading hundreds of containers, they managed to unload thousands of advance forces into the bay before jets were scrambled to sink the ships. Unprepared for an attack from within, the Lenehenese militia were cut to pieces by the well-trained Babylonian regulars in the Battle of Thridia the city fell within the hour. Having failed to prevent the Babylonians claiming a beachhead on Lenehenese soil, the Imperial Guard grinded into action and marched south.
Days rolled into weeks and weeks into months, but with every minute that passed the Babylonian army marched ever closer to Terra. Negotiations ceased as it became obvious that no respite was to be given by the enemy, whilst there was little hope of CREEEEEED and Carloso joining the war. Thridia was the first city to fall, quickly followed by Elysia, Castellax and even the legendary Mordia was no match for the endless armies of Emperor Xavier. Several attempts were made to break the Babylonian lines but none were successful.
With no end in sight, the Allies poured all efforts into a last-ditch stand against the formidable Babylonian 4th Army by taking a stand at Sularia Pass in the Van Der Marr mountains. Dozens of regiments from all over Lenehen and her allies were raised to defend the pass, the only gap through the mountains large enough to bring an army that had hope of sieging Holy Terra. For hours the defenders and the 4th Army was embroiled in the Defense of Sularian Gate but eventually the Allies emerged victorious. At this point, the war began to turn in the favour of the Allies- the Kieldar Offensive launched by Shalum utterly crushed the Babylonian 7th Army and any hopes of taking Terra. With blood and sweat, the Babylonians were pushed back to the coast where they made a desperate last stand in the Second Battle of Thridia, but were ultimately crushed. The tides had turned, and it was time to take the fight to Babylonian soil.
Numerous amphibious assults were made against New Babylonia, attempting to take enough ground to start flying in heavy armour and supplies from nearby Panzermee. After much bloodshed, eventually a beachhead was made in the north-west and now the fight could be brought to the enemy. After months of bloody urban fighting, the Allied army were within 50 miles of Babylon, the capital city, if it could be taken the war was over. But whilst the fighting in Babylonia was fierce, the international negotiations were fiercer- alarmed by the sudden change in the course of the war and the potential that it was now Lenehen that could become too powerful, CREEEEEED and Carloso demanded that Lenehen and the Coalition withdrew from New Babylonia and all territorial changes were to return to their owners ante bellum or they would enter the war on the side of the Babylonians. After much thought, the Coalition refused- simply too many lives had been lost to give up their gains. But now the game had changed, the enemy was now no longer on the defensive- what was to stop Babylonia's new allies from rampaging across their now-undefended homelands? Eventually it was decided, Lenehen was to continue the march towards Babylon whilst Shalum, Kelonna, Bankampar and Panzermee were to tie down CREEEEEED and Carloso until victory could be achieved.
Due to Emperor Xavier's bordering-psychotic obsession with militarism, the city of Babylon was more of a fort than a capital city. Earthworks covered the surrounding hills, fearsome batteries of heavy weapons dotted the landscape and city walls large enough to rival the great walls of the Imperial Palace in Terra all stood to deter even the most able attacker. But too much had been lost to give up hope now, the cities defences seemed formidable but no cost was too high in exchange for taking Babylon, and possibly the Emperor himself. Dead or alive, it mattered little to the Lenehenese. Although the war was seemingly at an end, this was no time to become overconfident- the city still had millions of soldiers and civilians, all fanatical in their devotion to their cause and they must first be overcome. 14 million soldiers of the Death Korps of Krieg, experts in grinding siege warfare, were mustered and brought to the front and the war culminated in the infamous 14-month Siege of Babylon. When the battle proved costly and indecisive, a peace was declared and all territory returned to their owners ante bellum, albeit with massive battle-damage.