Aeter had spent many years in hiding from the Goraeshians slowly raising an army to avenge the destruction of his city and his King. This rising threat was not lost on King Gorain XII but he was ailing in his old age and in poor health eventually his son Gilesh II had begun to rule as King of Goraesh in all but name. Gilesh II while a relatively competent administrator, was far too ambitious for his own good and often overestimated the skills and abilities of his armies. So when he heard of an upstart causing trouble up north he assembled an army as quickly as possible and rode out to meet this threat. Since 1404 at the conlusion of the previous war Kerick had been under the occupation of Goraesh. Aeter had a vested interest in retaking his kingdoms capital if he wished to rule it and free his people. The two armies met on the 4th of June 1422, the armies were relatively evenly matched with the tiebreaker being Aeter's tactical intelligence taking advantage of Gilesh's II overconfidence leading to a decisive Aeterosan victory in the Second Battle of Kerick. With his army defeated Gilesh II understood that withdrawal was the only way to avoid certain defeat fell back to his fortified capital city. Leaving Aeter and his army to reclaim Kerick. It is said that when Aeter attempted to crown the son of Tamar II ruler of Kerick his army left the city and refused to return unless Aeter were to crown himself. Whether this is truth or the work of future historians is unclear. What is known is that by August of 1422 Aeter had assumed Kingship of Kerick.
Not content to allow Gilesh II to rule his kingdom ever plotting his revenge, Aeter choose to take action and spent the next few years preparing to end this inter-island rivalry once and for all. Marching south with an army in the tens of thousands, the next few years would be a tactical chess match between Aeter and Gilesh II as they traded victories eventually Aeter was able to push Gilesh II to his breaking point with a final climactic battle taking place outside of Goraesh on the 15th of November 1425. At this point in the war the tides had shifted fully in favor of Aeter. Gilesh II was killed in the battle outside of the cities gates. With their King struck down the armies of Goraesh were firmly routed and Aeter marched into the city a victorious conqueror.
Understanding that the great tensions between his people and those of Goraesh would be a major point of division in his new kingdom Aeter moved his kingdoms capital from Kerick to Goraesh, both as a move to appear more friendly to his newly conquered subjects, and as a pragmatic move to make them easier to control.Aeter now crowned as King Aeter I would rule for an astounding 48 years, initiating great legal and economic reforms. King Aeter I would die peacefully in his sleep on the anniversary of his final victory on the 15th of November 1473. His son King Aeter II would succeed him and move the capital back to Kerick, believing the task of unifying the kingdom was complete by his father.