Earlier quoted context omitted.
> In Bavaria where I live, the informal convention is also last name first It's probably a Roman thing. Julius Caesar was actually "Caesar, of the gens Julia", so last-name first. In Italy we also used to list last-name first, particularly in official and military communications. This has changed significantly in the last 40 years, particularly in everyday bureaucracy, but it's still used by police and other bodies.
Roman naming conventions[1] technically did have a personal first name that came first and was called that: first name or forename is a reasonably direct translation for praenomen. The complexity is that by the late republic praenomina were largely from such a small set of names that they were not particularly useful to distinguish anyone, and they became somewhat of a formality that would often be omitted. Julius Ca…
So Caesar's close relatives were all also called Caesar, which is how it got to be an imperial title. You might think that with the original cognomen locked into place for such families, members would get a second cognomen so that there would be at least one part of their name that could identify them. But apparently not.