Chronology of World War II
French advance into Germany ends
Tuesday, September 12, 1939 www.onwar.com
On the Western Front... French forces have now advanced about 5 miles (8 km) into Germany on a 15-mile (24 km) frontage in the Saarland region. The French claim that the action has forced the Germans to withdraw 6 divisions from Poland, although British observers express doubts. The advance places the front within half a mile of the Siegfried Line and a frontal assault on this defensive system is considered to be out of the question.  General Gamelin calls an end to the Saar offensive.

In Poland... Some of List's troops are fighting near Lvov while others are moving north from their bridgeheads over the San. The Polish army around Poznan, the one that was to have marched on Berlin, unexpectedly turns about and attempts to take the German 8th Army in the flank. This is the start of the violent battle of the Bzura River. Polish troops push the German forces 12 miles south of Kutno and recapture Lowicz. Gdynia is evacuated by the Poles. Luftwaffe planes bomb Krzemieniec (Kremenets) in eastern Poland, a declared open village where the diplomatic community from Warsaw has sought refuge.

In Bucharest... The German Foreign Minister, von Ribbentrop, demands that the Romanians not give asylum to Polish officials crossing the border and threatens military action in case of noncompliance.

In France... The Anglo-French Supreme War Council meets for the first time at Abbeville. Meanwhile, a Czech army-in-exile is formed.

In Britain... The home office opens an inquiry into blackout rules.

In the North Atlantic... The US Navy begins regular neutrality patrols along the entire length of the eastern seaboard and in the Caribbean.


This chronological study of the Second World War provides a comprehensive day-by-day account of WWII. While focused on the military history of the war, with an emphasis on the battles and campaigns fought, the timeline includes social and political history as well. Some Holocaust related events are already recorded and additional updates are pending. In so far as possible, the images included in this presentation are pictures from the given days. Additional information and images are welcome through the feedback form found on the index.