With the death of High King Thassad II, a civil war erupted in Hammerfell between the two major factions, Crowns and Forebears. The king's son Prince A'Tor fled to Stros M'Kai after Sentinel was captured and gathered his forces. The Crowns won many battles and planned to retake the capital, but the Forebears signed a treaty allying themselves with Tiber Septim and his Empire. Imperial Legions and Forebears combined were no match for the Crowns. Knowing the fate of his kingdom was at stake, the Prince prepared to make his last stand.
Before Iszara joined the rebels, they were little more then "a wild pack of nationalists with sharp sword and enthusiastic schemes." They worked for A'Tor in secret, removing Forebear traitors on the mainland and killing Imperial emissaries who lingered too long on their borders. The League was forced to watch from afar during the Battle of Hunding Bay, since the prince could not risk openly affiliating with them. During the conflict, the prince was mortally wounded by the poisoned arrow from the Dunmer assassin Dram and, in a desperate attempt to save his life, the arch-mage Voa trapped the prince's soul within a gem, which would later come under the League's safekeeping. While Basil mourned his death, Iszara, frustrated with the League's indecisiveness, stole the soulgem and fled to Stros M'Kai to find a way to resurrect the prince. Cyrus made his way to the League's hideout and spoke to Basil to uncover her whereabouts, but found little that he did not already know.
When Cyrus succeeded in locating and freeing Iszara, she made her way back to the hideout and together concocted a plan for retrieving the lost soulgem and finding someone to bring the heir to the throne back to life. Basil promised Cyrus that "when you have the prince, you have his men."
With preparations made, Cyrus sent Coyle to signal the Restless League from the Saintsport's Lighthouse. After sneaking the Yokundan gypsy Saban into the Temple of Arkay, Basil and his men docked in and killed the nearby Imperial guards before arriving at the temple themselves. When the resurrection failed, placing the soul of A'Tor in his sword rather then his body, Basil threatened to abandon the cause until Cyrus gave a rousing speech, promising to go to the palace and kill the provisional governor Lord Amiel Richton himself with the now enchanted royal blade. Basil and the Restless League then took to the water again, securing the harbor and destroying the Empire's ships.