Preceding Germanisation, numerous Prussian tribes inhabited Prussia, exhibiting pagan beliefs.[1] Accordingly, religious as well as economic and political factors inspired eastward German expansion, in what was later regarded as the Drang nach Osten (push to the east).[1] Whilst conquest was predominately violent and entailed large scale resettlement measures, there were cases of native nobles utilising the presence of foreigners in order to gain a local advantage, resembling to some extent a capacity for cooperation.[2] However, the subjugation of native tribes did not ensure their immediate eradication, as natives otherwise retained their lifestyle, resulting in their gradual absorption into larger population sects over the following centuries.[2] It is speculated that this preservation of local inhabitants' rights for so long can be attributed to their importance in fulfilling military functions for their new rulers.[1] Conversely, the worth of Prussia and neighbouring territory has been questioned by some academics, thereby explaining the neglect of the broader Baltic region by its Christian neighbours until the 13th century.