This paper is an endeavor to evaluate the activities of Mahmoud Nadeem, the Syrian Pasha who worked as Wali in Yemen in the period 1913-1917. At that time، Yemen was one of the important strategic points during the first World War and، hence، became the scene of intense fighting and conflict of interests. The paper highlights the role of Pasha Mahmoud Nadeem before the First World War when he was the official representative of the Ottoman Empire in Yemen. Then it presents his Arab-nationalistic role to protect Yemen against the growing colonial interests of Britain after the end of the war. In addition, the paper shows up his contributions in fostering the rule of Imam Yehia Hameed-Adeen and the suppression of the separatist movements which rose against the latter.