Anyone with an Irish citizen grandparent born on the island of Ireland is eligible for Irish citizenship. His or her parent would have automatically been an Irish citizen and their own citizenship can be secured by registering themselves in the Foreign Births Register. In contrast, those wishing to claim citizenship through an Irish citizen great-grandparent would be unable to do so unless their parents were placed into the Foreign Births Register. Their parents can transmit Irish citizenship to only those children born after they themselves were registered and not to any children born before registration.