Britain: Commissioning of first purpose-built (from keel up) seaplane carrier HMS Ark Royal II (launched September 5). First carrier with hangars below deck, but unable to fly off or land her 5 floatplanes and 2 land planes which are lowered and raised over ship’s sides by pair of cranes.
Serb Second Army reoccupies Lazarevac, while other pursuers retake Uzice. Potiorek orders general Austrian retreat in evening. Putnik orders continuation of offensive.
Joffre rejects British proposal that BEF be transferred to extreme left of Allied line to permit combined operations along Belgian coast, as a ‘mouvement eccentrique’.
Mesopotamia: Subhi Bey surrenders Qurna (1242 PoWs and 9 guns taken since December 4); British 331 casualties
Southeast Cameroons: 610 French soldiers force Germans to evacuate Baturi.
Eastern Front: Warsaw bombed by German aircraft, US Consulate damaged.
Britain: Ahlers, the ex-German consul of Sunderland, sentenced to death but reprieved on December 18.