British treaty with al-Idrisi

A British chronology of the war records under 28 April 1915 the conclusion by the British government of an agreement with Muhammad ibn Ali al-Idrisi, ruler of the Emirate of Asir on the south-western coast of the Arabian Peninsula. The agreement was to secure cooperation against the Turks. The document kept in the archives of the British India Office, however, is dated 30 April 1915, and that is the date given by most studies. The discrepancy may have arisen because the day on which the negotiations were concluded differed from the day of signature, but we have not been able to establish this.

A treaty of friendship

The British had been looking for allies among Arab rulers from the moment the Ottoman Empire entered the war. Idrisi was an obvious candidate. Since 1909 he had been fighting the Turks for control of the lowland Tihamah and the coast of Asir, and in January 1915 his men occupied the Farasan Islands in the Red Sea. The negotiations were conducted by the British Political Resident in Aden, who was subordinate to the authorities of British India. On the British side the agreement was signed by the Resident, D.G.L. Shaw, and his First Assistant, Harold Fenton Jacob, and on Idrisi’s behalf by his plenipotentiary, Sayyid Mustafa ibn Abd al-Ali. The document was called a treaty of friendship and goodwill, and its contents were kept secret.

The obligations of both sides

Idrisi undertook to wage war on the Turks and to strive to drive them out of Asir. The treaty allowed him to extend his lands at the Turks’ expense, but forbade him to act against the Imam of Yemen, Yahya, as long as the latter did not side with the Turks. The British wanted their ally to fight the Ottoman forces rather than drag them into his quarrels with his neighbours. At the same time the alliance with Idrisi was to be a counterweight to the Imam, who had been an ally of the Turks since 1911 and whom the British saw as a threat to Aden.

In return Britain guaranteed Idrisi the independence of his lands and protection against attack, and also promised to help settle his dispute with the Imam after the war. Idrisi was to receive money and arms. According to Jacob, the British supplied him with large quantities of rifles and ammunition, as well as guns and mortars. The treaty also provided for the opening of Idrisi’s ports to trade, which was extremely important for a state living from exchange across the Red Sea.

The first Arab ally

The agreement with Idrisi is regarded as the first treaty concluded by Britain during this war with an Arab ruler who openly stood against the Turks. It was also the only document in which a foreign power recognised Idrisi’s rule over Asir. For the British the alliance mattered above all strategically. Idrisi’s forces could cut the land communications between the Turkish garrisons in the Hejaz and in Yemen, and his control of the coast deprived the Turks of ports from which they could threaten shipping. Indirectly this also protected Aden, in whose hinterland there had been clashes with the Turks since February.

The results proved more modest than expected. Idrisi’s forces, supported by British ships, fought the Turks on the coast of the Tihamah in the following months, but failed to drive them out of the mountain strongholds of Asir. Idrisi himself was a cautious ally, because he feared both the Turks and Imam Yahya, as well as the mood of his own tribes. In January 1917 the British concluded another agreement with him, in which they recognised the Farasan Islands as part of his state.