The North Yemen Civil War began when Abdullah al-Sallal dethroned the newly crowned Imam al-Badr and declared Yemen to be a republic under his presidency.

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.

Abdullah Yahya al-Sallal was a Yemeni military officer who was the leader of the North Yemeni Revolution of 1962 and served as the first President of the Yemen Arab Republic from 27 September 1962 until his removal on 5 November 1967. It was his government that abolished slavery in Yemen.

Muhammad al-Badr was the last king and Zaydi Imam of the Mutawakkilite Kingdom of Yemen and leader of the monarchist regions during the North Yemen Civil War (1962–1970). He was Imam and Commander of the Faithful and King of the Mutawakkilite Kingdom of Yemen.

The Yemen Arab Republic, also known as Yemen (Sanaʽa) and was commonly referred to as North Yemen, was a country that existed from 1962 until its unification with the People's Democratic Republic of Yemen in 1990, in the northwestern part of what is now Yemen. Its capital was at Sana'a. It bordered the South Yemen to the southeast, Saudi Arabia to the north and Red Sea to the west, sharing maritime borders with Djibouti and the People's Democratic Republic of Ethiopia.