[cherryteastain]

> Very early in the empire, a law made all conquered people officially Roman

Wouldn't call this "early" in the empire. Caracalla [1] did this in 212AD by granting Roman citizenship to free noncitizens, well after the beginning of the empire in 27BC. W Roman Empire fell in the late 470s so about half of the empire's lifetime had severe legal stratification between citizens, free noncitizens (peregrini) and slaves.

[1] https://en.wikipedia.org/wiki/Constitutio_Antoniniana

[jcranmer]

The Roman Republic notably granted citizenship status to most of the socii during the Social War in the early first century BC. Even discounting one-off mass citizenship grants, Roman citizenship was much easier to obtain than pretty much every other Mediterranean polity (in large part by dint of it being even possible in the first place).

[constantius]

Fair. I believe the Empire only ended with Byzantium, and as far as I know the edict was never repealed, but I do differentiate between Rome and Byzantium elsewhere, so I see the point.