Marne: GERMAN RETREAT BEGINS in high winds and drenching rain. Colonel Hentsch, Head of Foreign Armies (Intelligence) Department at GHQ – Moltke’s peripatetic ‘troubleshooter’ – arrives by car at Bülow‘s HQ, Bülow learns BEF have crossed river Marne. Kluck continues determined efforts to crush Maunoury, retaking Nanteuil. Shortly before 1200 hours Hentsch reaches Kluck’s HQ and tells Kluck that, since Bülow now being forced back towards river Vesle and Kluck’s own army at risk of double envelopment, a coordinated retreat to the Aisne is necessary. Kluck issues retreat order at 1100 hours.
BEF pushes 4 miles (6.44 km) north of the Marne, d’Esperey gives Foch X Corps and issues inspirational ‘Order of the Day’ to Fifth Army. Sir J French orders BEF to continue pursuit at 0500 hours. Joffre orders a combined attack; the BEF moving northeast with its left on Soissons; d’Esperey, on its right, to reach river Marne and establish bridgehead at Chateau-Thierry. Maunoury, on the left, is to push north and envelop German right wing. Though these orders issued at 0145 hours, Maunoury only starts 1400 to 1600 hours as air scouts detect German columns in retreat.
Kluck, trying to pass northeast across Allied front to regain touch with Bülow has running fights with BEF advance guard and has to reroute his forces.
Belgium: Kaiser orders capture of Antwerp; General Beseler put in command of siege operations. Royal Navy armored train with 6 x 4.7-in guns joins Belgians as they make 2nd sortie (until September 13) with 6 divisions advancing up to 15 miles (ca. 24 km) and forcing German IX Reserve Corps to halt march south, but incurring 8,000 casualties.
Lorraine: French night attack fails but German VIII Corps advances back to river Meurthe on September 12.
East Prussia: Francois cuts off Russians before Lötzen, taking 60 guns and 5,000 PoWs, having marched 77 miles (ca. 124 km) in 4 days.
Galicia: Both sides attack in the widest fighting yet. Conrad drives to Grodek.
Hungary: Serbs capture two villages west of Belgrade after heavy fighting until September 10. Belgrade garrison occupies Semlin on the opposite side of the river.
Bosnia: Montenegrins again invade, capturing Visegrad on September 14.
Serbia: Hungarian composer (Bartok contemporary) Aladar Rado killed at Boljevci, river Sava, aged 32.
Pacific: Australian cruiser HMAS Melbourne occupies Nauru Island and destroys German radio station.
Germany: German Chancellor’s secret ‘September Programme’ lists massive war aims.
Kaiser’s pro-Muslim proclamation. Muslim PoWs will be sent to Caliph (Sultan at Constantinople).
1st War Loan opens; thereafter six-monthly.