Ahmad bin Yahya
Arab nationalism influenced some circles that opposed the lack of modernization efforts in the Mutawakkilite monarchy. This became apparent when Imam Ahmad bin Yahya died in 1962. He was succeeded by his son, but army officers attempted to seize power, sparking the North Yemen Civil War. The Hamidaddin royalists were supported by Saudi Arabia, Britain, and Jordan (mostly with weapons and financial aid, but also with small military forces), whilst the republicans were backed by Egypt. Egypt provided the republicans with weapons and financial assistance but also sent a large military force to participate in the fighting. Israel covertly supplied weapons to the royalists in order to keep the Egyptian military busy in Yemen and make Nasser less likely to initiate a conflict in Sinai.