4 February

1915 (Thursday)

 * British casualties on Western Front to this date approximately 104,000.
 * Continued heavy fighting on Bzura-Ravka front; Russians cross Bzura and take positions near Dachova.
 * Russians falling back in Bukovina.
 * The Winter Battle in Masuria (East Prussia) begins (see 22 February).
 * Actions on the Suez Canal end (see 3 February). Turkish forces retreat into Sinai.
 * German attack on Kakamas (north-west Cape Colony) repulsed.
 * German Government declare waters round the United Kingdom a "war region" as from 18 February.