The Battle of Es Sinn was a World War I military engagement between Anglo-Indian and Ottoman forces. It took place on 28 September 1915, during the Mesopotamian Campaign. The sides fought to determine control of the lower and rivers, in what is now Iraq. The British and Indian governments also viewed it as a test of the Ottoman forces, and whether a further advance to capture Baghdad was possible. The Anglo-Indian forces of Indian Expeditionary Force D were under the command of Major-General Charles Vere Ferres Townshend, and the Ottoman forces by Colonel Nureddin.