The Battle of Sheikh Sa'ad lasted from 6 to 8 January 1916. It was a part of the Mesopotamian Campaign during the World War I. The location of the battle was along the banks of the Tigris River. This was the first engagement by the Tigris Corps trying to break through the lines of the Ottomans.
On 3 January 1916, Aylmer ordered Younghusband to advance upriver. He was responsible for: 35th, 28th and 19th Indian Brigades. During that time, Aylmer stayed at Ali Gharbi. He waited for further reinforcements. He also retained, the 21st Indian Brigade and Tigris Corps’ cavalry. Younghusband was instructed not to heavily engage until he receives the reinforcements. He didn’t have any cavalry, so his loses would be huge. Also, the weather conditions were very bad, so airplanes (a few) couldn’t be used by the Tigris Corps. Younghusband wrote that his forces weren’t enough for a battle against Ottoman forces. On 5 January 1916, he was informed that the Ottoman forces are upriver. On the next day, they bumped into those positions.
The Tigris Corps were successful and they took over control over the positions. However, breaking the Ottoman lines had a significant cost. They lost 1.962 soldiers. 2.300 were wounded. They had at their disposal, 13.300 soldiers. During the battle, the Tigris Corps ambulances were prepared to treat 250 injured soldiers. However, the field ambulances had to take care for 10 times more than that during and after the battle.
The battle ended with British tactical victory. But, the number of casualties was 4.262 soldiers. On the other side, the Ottomans lost 1.200 soldiers.