is uncertain. He claimed to have taken up the to set the land free, but the exact meaning of is unknown; their removal seems to have been part of the problem of – another word whose meaning is obscure. Solon was also credited with abolishing slavery for debtors, and establishing limits on who could be granted Athenian citizenship. Solon instituted radical constitutional reform, replacing noble birth as a qualification for office with income. The poorest – called thetes – could hold no offices, although they could attend the Assembly and the law courts, while the richest class – the pentacosiomedimni – were the only people eligible to become treasurer, and possibly archon. He set up the Council of the Four Hundred, responsible for discussing motions which were to come before the Assembly. Finally, Solon substantially reduced the powers of the archon by giving citizens the right of appeal; their case was judged by the Assembly. A second wave of constitutional reform in Athens was instituted by Cleisthenes towards the end of the sixth century. Cleisthenes apparently redivided the Athenian population, which had previously been grouped into four tribes, into ten new tribes. A new Council of 500 was instituted, with members from each deme represented. Demes were also given the power to determine their own members (which, in turn, provided them with influence over the membership of the citizen body more generally) and to somewhat determine their own judicial arrangements. These reforms gave the citizen body a sense of responsibility for what happened in the community for the first time. Between the reforms of Solon and Cleisthenes, the Athenian constitution had become identifiably democratic. Sparta Sparta's constitution took on the form it would have in the Classical period during the eighth century BC. By the classical period, Spartan tradition attributed this constitution to Lycurgus of Sparta, who according to Thucydides lived a little over four centuries before the end of the Peloponnesian War, around the end of the ninth century. The First Messenian War, probably taking place from approximately 740 to 720 BC, saw the strengthening of the powers of the Gerousia against the assembly, and the enslavement of the Messenian population as Helots. Around the same time, the ephors gained the power to restrict the actions of the kings of Sparta. Thus by the late seventh century, Sparta's constitution had recognisably taken on its classical form. From around 560