The background: in 1903 and 1904, the British and Ottomans cooperated in a Boundary Commission to survey the Border between the Aden Protectorate and Ottoman-controlled Yemen. This led to the demarcation of the border which would survive the end of Turkish rule in Yemen in 1918, and even the British departure in 1967, and remained the boundary between North and South Yemen until unification in 1990.
Recall that British control in South Arabia was exercised in two ways: the Aden Colony, which consisted of the port of Aden and its environs, and certain key islands, including Perim; and the Aden Protectorate, which was a looser British protectorate over the local sheikhs in the interior. Aden Colony was governed, at the time, from India, and was a critical fueling port between Suez and India.
In November 1914, with Britain and the Ottoman Empire at war, the British became particularly concerned over an Ottoman buildup on the Sheikh Sa‘id Peninsula directly opposite Perim Island, which was controlled by Britain and covered the northern approaches to the Strait of Bab al-Mandab. The Ottomans had built a fortification called Turba Fort (turba usually means "tomb" and I assume there was one in the locality). This was considered a threat to Perim and thus to the British lifeline to India. The 1940s era-map at left shows the strategic setting.
The problem was, the Aden garrison consisted of only one Indian and one British battalion and a small cavalry force, though there were plans to reinforce; the Ottoman VII corps was deployed in Ottoman Yemen. (By early 1915 it consisted of the 39th and 40th divisions; it isn't clear to me if that was the case in late 1914, and the British were unsure at the time.)
|Armored Cruiser HMS Duke of Edinburgh|
Duke of Edinburgh shelled the fort on November 10 and largely destroyed it; three battalions of the 29th, along with elements of the 23rd Sikh Pioneers, landed and engaged the local Turkish force, which retreated.They were joined by a naval demolition party and destroyed the fort, artillery, and other equipment. It was felt that it would be difficult for Turkey to resupply these in wartime, and so after spending November 11 destroying armaments, the Indian forces re-embarked and continued to Suez.
This German map details the landing sites and ship positions, or purports to. The German caption reads, "The British-Indian landing force with the armored cruiser (Panzerkreuzer) HMS Duke of Edinburgh and three fast troop transports." As you can see, the Turba Fort lay just over the border (dashed-dotted line).
Here is the account in the official British History of the Great War - Naval Operations, Volume 1, to the Battle of the Falklands, December 1914 (Part 2 of 2) by Sir Julian S Corbett:
Simultaneously [with operations in Mesopotamia] an equally rapid, and unexpected blow was delivered in the mouth of the Red Sea. At Sheikh Syed, opposite Perim, and just outside the northern limit of the Aden Protectorate, a mixed force of Turks and Arabs was reported to be assembling. Here a strong work known as Fort Turba was in a position, if adequately armed, to command the passage between Perim and the mainland. The force which the enemy had assembled was also strong enough to threaten Perim itself, and Aden and the Indian Government thought it advisable to deal with it at once. The means were at hand.
Another large convoy with five infantry brigades and the Imperial Service Cavalry Brigade had left India for France and Egypt on November 2, under escort of the Duke of Edinburgh, Swiftsure and Northbrook, the Duke of Edinburgh being under orders for home to join the Grand Fleet. The troops were urgently required in France, but the assent of the Home Authorities was obtained for a detachment of them to undertake the operation on their way, provided it would not delay the convoy more than twenty-four hours Accordingly, on November 8, as the convoy approached Aden, Captain Henry Blackett in the Duke of Edinburgh, with the City of Manchester and two other transports, containing three battalions of Indian Infantry under Brigadier-General Cox, was sent ahead at full speed. At daybreak on the 9th he closed the fort, and after laying it in ruins without drawing a reply, he led the three transports to a point within the Strait, near Sheikh Syed. Here a landing was at once effected in the face of considerable opposition and a galling fire, and the Duke of Edinburgh was able to keep it under sufficiently for a covering position to be seized without much loss. The disembarkation could then proceed, and early in the afternoon, when half the troops were ashore, an advance was made, still in the face of opposition, to clear the enemy away from the vicinity of Fort Turba. The enemy, however, eventually made off before it, and by night all the surrounding heights were occupied. Then, the following morning, without any interference, Captain Blackett was able to land a demolition party at the fort. It was found to contain only five light guns. These were destroyed, the work itself was completely dismantled, and by 6 p.m. all the troops were on board again, and the transports hurrying on to rejoin the convoy after a very clean and rapid piece of work.