Units of the 37th Indian Brigade began to land at Basra on 21 January 1916 and the brigade was formed in the next month. It served in the Mesopotamian Campaign for the rest of the war. It was attached to the 3rd (Lahore) Division from March to April 1916. While with the division, it took part in the attempts to relieve the 6th (Poona) Division besieged in Kut, including the Attack on the Dujaila Redoubt (8 March) and the action of Bait Isa (17 – 18 April).