Promoted to the rank of general in November 1903, Kuroki was appointed commander of the Japanese First Army upon the outbreak of the Russo-Japanese War the following year. After landing his forces at Chemulpo near Seoul in mid-February, Kuroki advanced north routing a smaller Russian force at the Battle of the Yalu River on 30 April-1 May 1904. Commanding the Japanese left flank at the Battle of Liaoyang, he repulsed a disorganized Russian attack from 25 August-3 September.