Rome kept changing who counted as Roman

Roman citizenship was not a fixed ethnic badge. Over centuries it could be granted to individuals, communities and discharged soldiers; after the Social War it spread widely through Italy. In 212 CE, Caracalla’s edict extended citizenship to nearly all free inhabitants of the empire.

Expansion did not make residents equal. Status, wealth, gender, enslavement and local privilege still arranged lives sharply, while historians debate Caracalla’s motives, including taxation. The useful surprise is narrower: Rome’s governing identity grew partly by admitting conquered people into a legal category whose meaning kept changing.