Thanks for the A2A.
In principle, this is not so easy to say in Germany.
Many cities that were founded in the more recent past, say in the last 117 years, existed even before their foundation as a settlement, hamlet, village or other structure, see e.g. Eisenhüttenstadt[1 (1951), which Joachim Pense had already written).Even Wolfsburg[2, as a pretty “new” city can’t keep up
In addition, there are always cities that have only recently been granted town rights, or cities that have been merged, so are not really “new” technically, prominent in recent history would be Dessau-Roßlau[3.
Leinefelde[4 would also be a candidate for the newest city in Germany:
In contrast to the endless expanses of America, Siberia/Russia, Australia or Africa, it has long been very difficult in Germany to re-establish a city in a previously undeveloped place.Our country is simply too small and old for that. Especially since a new town in an undeveloped place would hardly pass environmental policy – and which municipality gives or gave up land voluntarily in the period since the Second World War, so that someone can found a new city here?
Districts are and have been regularly redeveloped, including large ones:
A good resource for the candidate that meets your criteria, which are not defined here, you can find here: List of German city foundations – Wikipedia – in the 20th century my candidate Rodgau [5 , according to stricter criteria ( settlement refoundation), in the 19th century one even finds with documentary mentions, even with e.g. Ludwigshafen [6 – but also here applies: The Romans / Slavs / Celts / Franconia / Neanderthals have certainly before here house.
I hope that helped you.