Constitutio Antoniniana.
The Constitutio Antoniniana, also known as Edit of Caracalla or or the Antonine Constitution, promulgated by Emperor Caracalla in 212/3 in order to unite Roman society, declared that all free men in the Roman Empire were given full Roman citizenship and all free women in the Empire were given the same rights as Roman women, with the exception of the dediticii, people who’d become subject to Rome through surrender in war, and freed slaves. For the 1st time, unitary citizenship was established in an area that included millions of people from different cultural backgrounds on 3 continents (Europe, Africa, and Asia). It’s the first in a series of world-historically important documents of civil and human rights and constitutional history.
Constitutio Antoniniana image link.
https://www.constitutio.de/de/bilder/constitutio-antoniniana-hochaufloesend