the previous capture of baghdad

From The Prize:

setting: World War I. The British fleet was in the process of transitioning from coal power to oil/gas power. "It was the wartime petroleum shortage of 1917 and 1918 that really drove home the necessity of oil to British interests and pushed Mesopotamia back to center stage. Prospects for oil development with the empire were bleak, which made supplies from the Middle East of paramount importance. Sir MAurice Hankey, the extremely powerful secretary of the War Cabinet, wrote to Foreign Secretary Arthur Balfour that, 'oil in the next war will occupy the place of coal in the present war, or at least a parallel place to coal. The only big potential supply that we can get under British control is the Persian and Mesopotamian supply.' Therefore, Hankey said, 'control over these oil supplies becomes a first-class British war aim."

In 1917 British forces captured Baghdad.