The Athenian answer to immigration
From our UK edition
What is it in our interests to do about immigration? The ancient Athenians came up with an interesting answer. Any non-Athenian who wanted to take up residence in Athens had to register as a metoikos (‘one who changes home’, metic) with the state and their local authority. They paid a monthly tax, were liable for military service, but could not own land or engage in politics. They had to find themselves a citizen sponsor, to support their application for metic status and (possibly) to continue to sponsor them when it had been granted. A metic thought not to have a sponsor risked enslavement. The purpose of all this was to ensure metics did not get ideas above themselves.