What is the oldest written source in this country that mentions this right?
Iraq
In Article 20, the Iraqi Constitution states that all citizens shall have the right to vote, elect, and run for office. The voting age in Iraq is 18 years old. (Constitute Project, “Iraq’s Constitution of 2005”).
References:
“Iraq 2005 Constitution.” Constitute. Accessed July 19, 2023. https://www.constituteproject.org/constitution/Iraq_2005.