Most parts of the Middle East were provinces of Ottoman Empire before World War 1 united under the flag of Ottoman Caliphate which muslims considered their religious & political head. But with one British agent UK ignited a revolt which turned the tide against Ottomans.
T.E Lawrence was the British spy who was sent to Arabia by Minister of War Winston Churchill to start an Arab nationalist war for independence. At start T.E Lawrence along with Sherif of Mecca and his sons faced problems.
Their first attack on holy city of Madina was repulsed and the ottomans counter attacked them to liberate the Holy City of Makkah which was under Sherif rule. At this critical time T.E Lawrence received arms & ammunition from Britain and adopted a new strategy to expand the war to other territories to stretch & defeat the Ottoman army, and they were successful.
The open war by the European powers such as the Gallipoli Campaign by the allied forces was a failure but the internal rift that they created through T.E Lawrence become successful.
In Gallipoli campaign UK, France, New Zealand & Australia combined their forces but failed to capture anything on the expense of 190,000 dead soldiers. But in Arab revolt they succeeded with few agents and some supply of ammunition. Through the Arab revolt under T.E Lawrence they killed 35,000 Ottoman soldiers and captured the whole Arab peninsula from Makkah to Damascus.