When Lucifer was defeated and sent to hell along with his Silver Bloods, he knew that he'd have to find a way to either convert or kill Blue Bloods. I know what you're thinking. Well, there's still Silver Bloods, right? Correct. There are some left. However, these where converted Blue Bloods. Anyway, back to the whole "kill Blue Bloods" plot. Lucifer decided to create creatures of the night. Ones that could only drink a Blue Blood. Creatures that could change shape from human form to a beastly one. A werewolf. Their life cycle was like that of a Blue Bloods. They had the same way of living, the whole reincarnation deal. However, they had a strict hate for Blue Bloods because every time they were reborn, the loss in Rome was beaten into them. Each werewolf name started with "A", regardless of the century. Why a? No one is really certain.
Lucifer decided to send his right hand man back to Earth with the new werewolves, making him one of them. He was to be the leader of the pack until they had killed all of the Blue Bloods and returned to hell. Aaron happened to be the leader during this time frame.
The previous leader, Axel, had been so close to getting the Blue Bloods when he'd taken Roanoke. However, he knew that unless he had more insiders at Plymouth, he wouldn't be able to overtake it. After picking off a few of the important figures in the Committee, he thought he was ready to move in. However, one of the Blue Bloods had managed to force Axel into an early slumber.
The werewolves had been terrorizing the Blue Bloods for centuries, each time upon their return more vicious and making easier prey of these "immortal" vampires. Werewolves were the same as Silver Bloods when it came to their menus, but their powers had some differences. The werewolves were slightly faster than vampires, as well as having a more heightened sense (smell, hearing, seeing, etc.). The devil made good work.
Present day werewolf society? They had the council, run by twenty-seven male werewolves who'd been the appointed co-leaders since the assent to earth. The werewolves were secluded, but merged themselves into human society. Only the strongest of vampires could tell their true identity, so Blue Blood youth were easy pickings. Now we come to the point where you began. With Aithne coming before a council asking if she was ready. Ready to accept a destiny? Probably not. Ready to start another war? Most definitely.