My grandfather, a doctor in the British Army marched through Iran in the 1920’s en route for Iraq or Mesopotamia as it was known then as part of the campaign to deal with aggression on behalf of the Ottoman Empire.
The British Indian Army played a significant role in the liberation of Baghdad. Amidst the confusion of the retreat a large part of the Ottoman army (some 15,000 soldiers) were captured. A week after the city fell, General Maude issued the oft-quoted Proclamation of Baghdad, which contained the famous line “our armies do not come into your cities and lands as conquerors or enemies, but as liberators“.
Khalil Pasha withdrew his battered Sixth Army up river and established his headquarters in Mosul. He had about 30,000 total troops with which to oppose Maude. In April, he received the 2nd Infantry Division, but overall the Ottoman strategic position was bad in the spring of 1917. After the capture of Baghdad, Maude stopped his advance. He felt his supply lines were too long, conditions in the summer made campaigning difficult and he had been denied reinforcements he felt he needed