From 1874, these protection arrangements existed with the tacit acceptance of the Ottoman Empire that maintained suzerainty of Yemen to the north, and the polities became known collectively as the "Nine Tribes" or the "Nine Cantons."

In 1928, the British established Aden Command, directed by the Royal Air Force, to preserve the security of the Protectorate.

Not included in the protectorate were Aden Colony and the insular areas of Perim, Kamaran, and Khuriya Muriya that were administered by it.

British protection came to be considered by some to be an impediment to progress, especially by promoters of Arab nationalism as reinforced by news from the outside received by newly available transistor radios.

He feared that a successful federation in the Shafi'i Sunnite protectorates would serve to encourage discontented Shafi'ites who inhabited the coastal regions of Yemen.

To counter the threat, Ahmad increased Yemeni efforts to decrease British control and, during the mid-1950s, Yemen assisted a number of revolts by disgruntled tribes against protectorate states.

The Emergency was caused largely by Arab nationalism spreading to the Arabian Peninsula, encouraged especially by the Socialist and pan-Arabist doctrines of the Egyptian president Gamel Abdel Nasser.

They were called in by the army for strikes against positions using "60 lb" high explosive rockets and 30 mm Aden cannon.

The Battle of Crater brought Lt-Col Colin Campbell Mitchell (AKA "Mad Mitch") to prominence.

Order was restored by the British, due mainly to the efforts of the 1st Battalion Argyll and Sutherland Highlanders, commanded by Lt-Col Mitchell.