Introduced in the novel Breaking Dawn, immortal children are human infants and toddlers turned into vampires. They are said to be so beautiful it takes just one look to be under their control. In addition, it is said that an immortal child's tantrum can kill people, since they cannot easily control themselves. Carlisle described them as adorable little children with smiles and dimples that would destroy a village in one of their tantrums.
It is presumed that while their mental age is stuck at the age they were transformed, they still have the vampiric gifts of enhanced strength and speed as well the the supernatural gifts of certain vampires.
Because they are too young to be controlled, the Volturi killed all those who could be found. Creating one has become the worst crime in the vampire world, under penalty of death for both creator and created. Under this law, anyone who knows about or stands by the child is also punishable under this law.
Even after the law was established, the Volturi captured two children to experiment on. However, no matter how many centuries they'd spent to teach them, they still could not be controlled or taught. Carlisle Cullen stumbled across these children during his stay in Volterra and learned of this law. After they determined that immortal children could not be tamed, they had the children destroyed.
In Book 3 of Breaking Dawn, Irina spotted Bella, Jacob and Renesmee hunting and mistook Renesmee for one, prompting her to report the child to the Volturi. Her mother Sasha had created an immortal child called Vasilii, and she had to witness her mother's and brother's executions.
Acting as the unofficial royalty of vampires around the world, the Volturi have implemented and are enforcing a number of rules of conduct, or laws, that all vampires are expected to obey or get sentenced to death if they don't comply with the laws. There aren't many of them, and they mainly concern the secrecy surrounding the existence of vampires.
- Hunts must be inconspicuous, with victims unlikely to be missed; their remains must be disposed of and territory must be changed often.
- Incapable of self-control, and therefore a threat of exposure, immortal children are not to be created. Sasha and Vasilii were executed under this law.
- Dealing with Children of the Moon, except for the purpose of extermination, is prohibited.
- False witness, regardless of intent, is forbidden. Irina was executed under this law.
- Hunting is forbidden in Volterra, the town of residence of the Volturi; their food is brought from outside, sometimes from quite far away.
- Attention should not be drawn and vampires should not be noticed in sunlight. The penalty of breaking this law is death. Edward Cullen was nearly executed for walking into sunlight.
- Newborn vampires must be trained before they can be released on their own. Methods have been identified to do so, and they often require more than one mature vampire to be used.
- By letting a newborn hunt wildly, the penalty will be death both to the newborn and its creator.
- Rebellion against the Volturi is prohibited. Of course, it is nearly impossible to succeed.
Throughout the centuries, many vampires are born after the laws were established, and every vampire was taught of these laws by their creator. Though they think of the laws as an accepted fact, they do not know that it is really the Volturi's scheme to maintain control of the vampire world. But to this day, many vampires still continue to obey this law. Like the Cullens are obeying, which leads them to move approximately every 6 to 7 years to stop talk in the human world.