The Isle Wars was a series of wars between 5BGD - 273GD fought between Nova Solarius and all the civilizations on the Celestial island chain. The multiple wars took place on both Sea and Land, with most of the fighting on the sea. The wars involved immense material and human losses on both sides. It began after Solus I conqured the islands of Zavis & Solais by attacking the nearest neighbooring island to expand the domain of Solarius.
The First Zōsenia-Solarian War was the first war in the Isle Wars, being from 5BGD-3BGD against the Kingdom of Zōsenia. It was mostly a naval war, with most land battles being skirmishes. At the start of the war, Solus sent a naval fleet to the island of Telcor. The Solarian Fleet was met by the Zōsenia fleet, or the Grey Rose Fleet, led by Saito Toshio to protect the harbor of Daizo. The Battle of Daizo was the first battle and ended up a Zosenia victory, and took another 6 months for Solarius to build a navy. During the 6 months, Zosenian fleets raided Southern Solais, pillaging villages upon the coast. It was 6 months later, on June 17th, that the Solarian Navy would once more strike again, this time at the Battle of Sous Waves, where the Solarian fleet would destroy the Zosenia fleet and have free reign until the Grey Rose Fleet arrived and destroyed the Solarian Fleet on October 20, 5BGD. There would be a back and forth for 1 and a half more years, where at the end, the Zosenia would hand over its trading rights in the Magna Sea for 10 years.
In 32GD, Solus III wanted to conquer the island of Daegol. He sent an offer to King Daemon II to purchase the island. Daemon refused and instead, decapitated the envoys and sent their heads back to Solus. Seeing this as a declaration of war starting the First Fae-Sol War. Solus raised a legion and a fleet to attack the Faelo Kingdom. The legion was called the Legion XIII Faelo and landed on Daegol on July 27th, 32GD. The legion marched on Sariard, starting the Seige of Sariard, after the victory of Sariard, the legion marched onto the regional capital of Daegol, Caeridal. After the disastrous defeat at Caeridal, the Solarian Legion left Daegol, resulting in a White Peace on 33 GD.
The Second Zōsenia-Solarian War (42GD-45GD) was started due to an incident where some local fishermen were killed by a galley of archers off the southern coast of Solais. With the Tenno refusing to apologize, Solus III declared war on Zōsenia to weaken their fleet. This was also the first time a nation joined the war without being directly involved, as the Motuasima Confederation joined the war on the side of Zōsenia. Solarius was outnumbered in terms of naval vessels and had suffered loss after loss in the beginning months of the war. It was only after the Battle of Meri did the tide turn in favor of Solarius. In the end, Solarius did weaken Zōsenia's navy but also suffered heavy losses. Due to the mass of casualties, both Solarius & Zōsenia had agreed to end the war with the Treaty of Goko.