* Ancient Greece and Rome: early forms were limited to smaller groups and did not include all citizens
* Enlightenment period: brought about new ideas about individual rights, liberty and the rule of law. This was the main influence of modern liberal democracy.
* American and French revolutions: helped to establish democratic principles such as constitutionalism and the separation of powers.
* Suffrage and Civil Rights Movements: the 19th and 20th centuries saw the expansion of the right to vote to women, minorities, and other previously excluded groups, as well as the civil rights movement that sought to end discrimination and promote equality.