of the constitution improved the economic position of the Athenian lower classes, it did not eliminate the bitter aristocratic contentions for control of the archonship, the chief executive post. Peisistratus became tyrant of Athens three times from 561 BCE and remained in power until his death in 527 BCE. His sons Hippias and Hipparchus succeeded him. After the fall of tyranny (510 BCE) and before the year 508–507 was over, Cleisthenes proposed a complete reform of the system of government, which later was approved by the popular Ecclesia. Cleisthenes reorganized the population of citizens into ten tribes, with the aim to change the basis of political organization from the family loyalties to political ones, and improve the army's organization. He also introduced the principle of equality of rights for all male citizens, isonomia, by expanding access to power to more citizens. During this period, Athenians first used the word "democracy" (Greek: δημοκρατία – "rule by the people") to define their new system of government. In the next generation, Athens entered its Golden Age, becoming a great center of literature and art. Greek victories in Persian Wars (499–449 BCE) encouraged the poorest Athenians (who participated in the military campaigns) to demand a greater say in the running of their city. In the late 460s, Ephialtes and Pericles presided over a radicalization of power that shifted the balance decisively to the poorest sections of society, by passing laws which severely limited the powers of the Council of the Areopagus and allowed thetes (Athenians without wealth) to occupy public office. Pericles became distinguished as the Athenians' greatest democratic leader, even though he has been accused of running a political machine. In the following passage, Thucydides recorded Pericles, in the funeral oration, describing the Athenian system of rule: The Athenian democracy of Cleisthenes and Pericles was based on freedom of citizens (through the reforms of Solon) and on equality of citizens (isonomia) - introduced by Cleisthenes and later expanded by Ephialtes and Pericles. To preserve these principles, the Athenians used lot for selecting officials. Casting lots aimed to ensure that all citizens were "equally" qualified for office, and to avoid any corruption allotment machines were used. Moreover, in most positions chosen by lot, Athenian citizens could not be selected more than once; this rotation in office meant that no-one could build up a power base through staying in a particular position. The courts formed