This is not a tribute to any ‘liberal’ temperament of the Romans in the modern sense of the word. They conquered vast swathes of territory in Europe and beyond, sometimes with terrible brutality; and they were often xenophobic and dismissive of people they called ‘barbarians’. Yet, in a process unique in any pre-industrial empire, the inhabitants of those conquered territories, ‘provinces’ as Romans called them, were gradually given full Roman citizenship, and the legal rights and protections that went with it.