I don't think you meant it like that, but Kaliningrad, or Königsberg is inhabited since a bit longer. For example Immanuel Kant lived and taught there.
Also the birth place of graph theory
https://en.wikipedia.org/wiki/Seven_Bridges_of_K%C3%B6nigsbe...
Obviously. But since the Russian occupation infamously expelled the natives completely, when I talk about “inhabited since 1945” in the context of people living there now, I’m obviously referring to the Russian population.