Old Prussia may refer to different entities, which were also territorially defined.
In political and territorial respect it refers to: In religious and territorial respect it refers to: Source: Der Große Brockhaus: Handbuch des Wissens in zwanzig Bänden: 21 vols., 15th totally revised ed., Leipzig: F. A. Brockhaus, 1928–1935, vol.
1: A–Ast, article: 'Altpreußen', p. 356.
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