أحمد بن يحيى
In 1950, Kennedy Trevaskis, the Advisor for the Western Protectorate drew up a plan for the protectorate states to form two federations, corresponding to the two-halves of the protectorate. Although little progress was made in bringing the plan to fruition, it was considered a provocation by Ahmad bin Yahya. In addition to his role as king, he also served as the imam of the ruling Zaidi branch of Shi'a Islam. He feared that a successful federation in the Shafi'i Sunnite protectorates would serve as a beacon for discontented Shafi'ites who inhabited the coastal regions of Yemen. To counter the threat, Ahmad stepped up Yemeni efforts to undermine British control and, in the mid-1950s, Yemen supported a number of revolts by disgruntled tribes against protectorate states. The appeal of Yemen was limited initially in the protectorate but a growing intimacy between Yemen and the popular Arab nationalist president of Egypt Gamal Abdel Nasser and the formation of United Arab States increased its attraction.