The Northern Front was one of two fronts (see
Polish Southern Front), created to coordinate the activities of armies fighting the advancing
Wehrmacht. According to Polish military planners, the Front was to be created out of units which had retreated southwards, after defending the border with
East Prussia, and reserve units, concentrated east of
Warsaw. The Front was supposed to defend the line of the
Narew river, but this was already impossible on September 10, the day of its creation. Another line of defence, along the
Bug river, also was impossible to hold, as units of the Northern Front were scattered after heavy fighting against the Germans. The
Modlin Army had withdrawn to the
Modlin Fortress, while
Independent Operational Group Narew had been broken into a number of smaller groups. The
Prusy Army, destroyed near
Piotrków Trybunalski and
Radom, was slowly recreated in the area of
Chełm. == Organization ==