That's Brandenburg aka 'Preussen' at the time of the Great Kurfürst (1610 - 1688)
red = what Johann Sigismund got 1608/10
yellow/green - new territotries under the Greta Kurfürst.
You may perhaps notice, that West Prussia still isn't part of Brandenburg, that the original
Kurfürstentum Brandenburg is in brown. You may not know, though, that the Herzogtum Preussen was the former
Deutschherren Provinz and didn't belong to the German Empire until it became of Brandeburg
From West to East (leaving out the African territories):
And here again ...