For quite a few years, europeans have held european citizenship. But what is the actual meaning of the phrase in law?
By that I mean, is a (say) person born and lifelong resident in Germany, a european citizen in the "strong" sense of effectively having dual german-european citizenship? Could they surrender German nationality and yet still remain a european citizen? Or is European citizenship a derived/secondary kind of thing, that the person doesn't have independently, but only has by virtue of they being a German citizen and German citizens having the status of European citizens for the time being?