From A Wiki of Ice and Fire
|The Last Storm|
|Conflict||War of Conquest|
|Place||Storm's End, the Stormlands|
|Result|| Targaryen victory|
Conquest of the Stormlands
Foundation of House Baratheon
After Aegon made his intentions of conquering Westeros and unifying the Seven Kingdoms under his rule, King Argilac Durrandon offered him the hand of his maiden daughter, Argella but he refused. Instead, Aegon offered the hand of his closest friend and bastard half-brother Orys Baratheon. Enraged, Argilac had the hands of Aegon's envoy’s cut off and sent them to Aegon with the message “These are the only hands your bastard shall have of me.”
After Aegon landed he sent Orys alongside his sister-wife Rhaenys, atop of Meraxes, to conquer the Stormlands. Even though Harrenhal had already fallen to Aegon and the dragonflame of Balerion, Argilac's men remained loyal to him. Argilac refused to die in the same manner as Harren the Black and amassed a host at Storm's End to meet Orys' host. Atop Meraxes, Rhaenys scouted Argilac's movements. As the two armies closed on each other, a massive storm, that would give a name to the battle, broke out. Argilac's knights charged but were slowed by the mud. They finally broke though but faced Rhaenys on Meraxes. The dragon was just as deadly on the ground as in the air. In the confusion, Argilac was thrown from his horse and found himself face to face with Orys Baratheon. Both took a wound but soon Argilac would get his wish and would die fighting. His death ended the battle.
After her father's death, Princess Argella barred Storm's End and declared herself Storm Queen. Nevertheless, her garrison, fearing to share the fate of Harren, revolted against Argella and delivered her to Orys, chained and naked. However, Orys treated her gently, removing the chains, covering her with his cloak and giving her food and wine.
Afterward, Orys married Argella and became Lord of the Stormlands. He took the sigil of House Durrandon, as well as his words, as his own.