How did Pericles’ citizenship law change who could be an Athenian citizen?

In 451 or 450 BCE, Pericles introduced a law that significantly restricted citizenship by requiring that an individual have Athenian parentage on both sides.1

Prior to this legislation, the criteria for citizenship were less restrictive, as the upper classes often engaged in foreign marriages. By mandating that both parents be Athenian, the law effectively excluded children of mixed parentage from the rights and benefits associated with being a citizen.12

Historians suggest several motivations for this change:
* Political Strategy: It may have served as a tool against political rivals, such as Cimon, who had a foreign mother.1
* Resource Management: It likely aimed to limit access to public office and state distributions, ensuring these benefits remained reserved for those with established Athenian lineage.1
* Social Exclusivity: It reflected a desire to preserve the social fabric of Athens by championing exclusivist tendencies against immigrants.1

While the law created a firm distinction in status, it did not restrict the economic opportunities of foreigners, who continued to work in the fleet and on public building projects.1