At the 1871 Unification of Germany, the Reich was established constitutionally as a federation of monarchies, each having entered the federation with a defined territory; and consequently the unitary nationalism of the 'German Reich' was initially specified (at Article 1 of the 1871 constitution) in territorial terms, as the lands within the former boundaries of this particular subset of German monarchies.[5] This geographical understanding of the German state became steadily superseded in the period up to the first World War by an understanding of Germany as a unitary nation state identified with the German national people according to the principle of jus sanguinis, and drawing on the rhetoric of "the sovereignty of the nation" in the Frankfurt Constitution;[6] albeit that many ethnic 'Germans' (as with the German-speaking peoples of Austria) remained outside the national people constituting the German Empire of 1871; and also that the Empire of 1871 included extensive territories (such as Posen) with predominantly non-German populations. This transition became formalised in the constitution of the Weimar Republic,[7] where Article 1 identifies the Reich as deriving its authority from the German national people; while Article 2 identifies the state territory under the Reich as the lands which, at the time of the constitution's adoption, were within the authority of the German state.