Abdullah al-Sallal in the context of President of North Yemen

The North Yemen civil war, also known in Yemen as the 26 September Revolution, was a civil war fought in North Yemen from 1962 to 1970 between partisans of the Mutawakkilite Kingdom and supporters of the Yemen Arab Republic. The war began with a coup d'état carried out in 1962 by revolutionary republicans led by the army under the command of Abdullah al-Sallal. He dethroned the newly crowned King and Imam Muhammad al-Badr and declared Yemen a republic under his presidency. His government abolished slavery in Yemen. The Imam escaped to the Saudi Arabian border where he rallied popular support from northern Zaydi tribes to retake power, and the conflict rapidly escalated to a full-scale civil war.

On the royalist side, Jordan, Saudi Arabia, and Israel supplied military aid, and Britain offered covert support. The republicans were supported by Egypt (then formally known as the United Arab Republic or UAR) and were supplied warplanes from the Soviet Union. Both foreign irregular and conventional forces were also involved. Egyptian President Gamal Abdel Nasser supported the republicans with as many as 70,000 Egyptian troops and weapons. Despite several military actions and peace conferences, the war sank into a stalemate by the mid-1960s. Egypt's commitment to the war is considered to have been detrimental to its performance in the June 1967 Six-Day War against Israel. Once the Six-Day War began, Nasser found it increasingly difficult to maintain his army's involvement in Yemen and began to pull out his forces. The surprising removal of Sallal on November 5 by Yemeni dissidents, who were supported by republican tribesmen, resulted in an internal shift of power in the capital, as the royalists were approaching from the north.

The 1967 North Yemen coup d'état was a bloodless overthrow of President Abdullah al-Sallal on November 5, 1967 in the Yemen Arab Republic. Yemeni dissidents and tribal forces carried out the coup, acting with the quiet approval of Sallal's main backer Nasserist Egypt.

This was due to a major shift in Egyptian foreign policy. Following the heavy defeat in the Six-Day War, Egyptian President Gamal Abdel Nasser lost much of his desire for costly foreign military adventures, including the war in North Yemen. Nasser announced plans to pull back from such commitments. In August 1967, Egypt and Saudi Arabia signed a peace agreement in Khartoum, requiring Egypt to completely withdraw its forces from Yemen. Egypt began pulling its troops out even before the agreement was fully implemented, completing the withdrawal by the end of the year. Reportedly, Nasser himself advised Sallal to step down and leave the country. When Sallal refused and instead flew to Baghdad seeking alternative support for his government, Nasser sent instructions to the remaining Egyptian troops in Yemen: they were not to intervene if the North Yemeni army moved against Sallal.