In the First World War, Younghusband was given command of the 28th Indian Brigade, part of the 10th Indian Division. They were initially deployed to defend the Suez Canal. Until 1916, when the brigade was sent to take part in the defence of Aden. It then moved to Basra to participate in the Mesopotamia Campaign. During the subsequent operation Younghusband was again mentioned in dispatches. His last command position was in 1916, as commander of the 7th (Meerut) Division, still in Mesopotamia, but he was forced to relinquish that position due to wounds received.