Some time after Bella and Edward's wedding, Bella receives a necklace from Aro. Alice had mailed the Volturi an announcement for Bella and Edward's wedding, and Aro in return sends Bella the necklace as a wedding gift. It is described as being ostentatious with a very large jewel, and is said to have been part of the English crown jewels.
Still some time later, Irina, a vampire from the Denali coven, comes to Volterra to inform the Volturi that the Cullens had created an immortal child. In response to this breach of theirlaws, the Volturi gathered the entire guard together (including the wives) and set out for Forks to destroy theCullens. Aro, meanwhile, intends to use the situation to try and force Edward, Bella and Alice into joining the Volturi.
When the Volturi arrive, they are shocked to discover what they believe to be a vampire army that the Cullens have assembled to oppose them, furthering Aro's belief they'd created an immortal child. Carlisle, however, is able to talk to Aro and offer his hand, saying that it was never his intent. Aro, to his credit, is willing to listen and is relieved to discover that Carlisle's 'army' are in fact witnesses. Bella also describes Aro "scanning the crowd" as though searching for a certain face - most likely Alice's - and Bella feels suddenly glad Alice isn't with them after all. The Volturi notice the line of werewolves behind Carlisle's witnesses. In his usual fashion, Aro acts as speaker for the Volturi. After reading Edward's mind and learning about Renesmee, the so-called immortal child, Aro is both astounded and delighted to discover that she is actually half human. He is also amused at the idea of having the werewolves, whom he believed were the Cullens' pets, as guard dogs. Unfortunately, the angry snarls from the wolves inform him that it would never happen.
Incensed at their defiance of the Volturi, Caius declares that Renesmee has to be killed, despite Aro's attempts to keep the encounter from turning violent, while Marcus is content to allow the child to live. Realizing Bella's mental shield rendered all the Volturi's powers useless, Aro knows they are at a huge disadvantage and has to do some fast and serious smooth talking to prevent the situation form turning for the worse. Soon after, Alice and Jaspershow up with another vampire half-breed named Nahuel. The knowledge that there are other half-breeds in the world heartened Aro and he was relieved to realize Renesmee would pose no threat. The Volturi left with their confidence somewhat shaken. Edward knows the Volturi (especially Caius) see them as a threat and expects them to try to pick them off one by one later. Aro desperately wants Edward, Alice, and Bella to join the Volturi, but in the end, he is genuinely saddened to lose Carlisle's friendship and hopes to regain it, and he's relieved that is all he lost; Aro is fully aware that the outcome could have been a great deal worse.
Though his coven have left the Cullens in peace, they expect that they will someday attempt to take them out in the name of revenge.
In Alice' s vision, he is beheaded by Bella and Edward after attempting to kill the both of them.