Career
In the Reichsgau Wartheland (Polish areas annexed by Nazi Germany), Jäger served as administrative chief to the regional leader Arthur Greiser. Earlier, Jäger had led the effort at Nazification of the Evangelical Church in Prussia. lieutenant was more or less Germanized in the other occupied territories, despite an encyclical issued by the Pope as early as 27 October 1939 protesting against this persecution.".