Germany: Mueller diary ‘The general war situation demands our ultimate weapon’ (unlimited U-boat war). Kaiser so orders Naval Staff on January 9. Greece: Allied ultimatum to government demands acceptance of December 31, 1916 terms. Greece accepts on January 10.
Rumania:Falkenhayn captures Focsani with 5,500 PoWs and crosses river Putna north and southeast of it on January 9, only to be repelled on January 10.