Yemen Arab Republic in the context of People's Republic of Southern Yemen

Yemen, officially the Republic of Yemen, is a country in West Asia. Including the Socotra Archipelago, mainland Yemen is located in southern Arabia; bordering Saudi Arabia to the north, Oman to the northeast, the south-eastern part of the Arabian Sea to the east, the Gulf of Aden to the south, and the Red Sea to the west, sharing maritime borders with Djibouti, Eritrea, and Somalia across the Horn of Africa. Covering roughly 455,503 square kilometres (175,871 square miles), with a coastline of approximately 2,000 kilometres (1,200 miles), Yemen is the second largest country on the Arabian Peninsula. Sanaa is its constitutional capital and largest city. Yemen's estimated population is 34.7 million, mostly Arab Muslims. It is a member of the Arab League, the United Nations, the Non-Aligned Movement and the Organisation of Islamic Cooperation.

Owing to its geographic location, Yemen has been at the crossroads of many civilisations for over 7,000 years. The Sabaeans formed a thriving commercial kingdom that influenced parts of modern Ethiopia and Eritrea. In 275 CE, it was succeeded by the Himyarite Kingdom, which spanned much of Yemen's present-day territory and was heavily influenced by Judaism. Christianity arrived in the fourth century, followed by the rapid spread of Islam in the seventh century. From its conversion to Islam, Yemen became a center of Islamic learning, and Yemenite troops played a crucial role in early Islamic conquests. Much of Yemen's architecture survived until modern times. For centuries, it was a primary producer of coffee, exported through the port of Mocha. Various dynasties emerged between the 9th and 16th centuries. During the 19th century, the country was divided between the Ottoman and British empires. After World War I, the Kingdom of Yemen was established, which in 1962 became the Yemen Arab Republic (North Yemen) following a civil war. In 1967, the People's Democratic Republic of Yemen (South Yemen) gained its independence from the British Aden Protectorate, becoming the first and only communist state in the Middle East and the Arab world. In 1990, the two Yemeni states united to form the modern Republic of Yemen, with Ali Abdullah Saleh serving as the first president until his resignation in 2012 in the wake of the Arab Spring.

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.

South Yemen, officially the People's Democratic Republic of Yemen (PDRY), abbreviated to Democratic Yemen, was a country in South Arabia that existed in what is now southeast Yemen from 1967 until its unification with the Yemen Arab Republic in 1990. The sole communist state in the Middle East and the Arab world, it comprised the southern and eastern governorates of the present-day Republic of Yemen, including the islands of Perim, Kamaran, and the Socotra Archipelago. It bordered the Yemen Arab Republic to the northwest, Saudi Arabia to the north, Oman to the east, the Arabian Sea to the southeast, and the Gulf of Aden to the south. Its capital and largest city was Aden.

South Yemen's origins can be traced to 1874 with the creation of the British Colony of Aden and the Aden Protectorate, which consisted of two-thirds of present-day Yemen. Prior to 1937, what was to become the Colony of Aden had been governed as a part of British India, originally as the Aden Settlement subordinate to the Bombay Presidency and then as a Chief Commissioner's province. After the establishments of the Protectorate and Federation of South Arabia amidst rising Pan-Arab and anti-colonial sentiment, an armed rebellion began in 1963 that was led by the National Liberation Front (NLF) and the Front for the Liberation of Occupied South Yemen (FLOSY) against British colonial rule. The Federation and Protectorate of South Arabia were overthrown to become the People's Republic of Southern Yemen (PRSY) on 30 November 1967.

The Yemeni unification took place on 22 May 1990, when the People's Democratic Republic of Yemen (South Yemen) and the Yemen Arab Republic (North Yemen) united, forming the Republic of Yemen.

The Arab Cold War (Arabic: الحرب العربية الباردة al-ḥarb al-`arabiyyah al-bāridah) was a political rivalry in the Arab world from the early 1950s to the late 1970s or early 1990s and a part of the wider Cold War. It is generally accepted that the beginning of the Arab Cold War is marked by the Egyptian Revolution of 1952, which led to Gamal Abdel Nasser becoming president of Egypt in 1956. Thereafter, newly formed Arab republics, inspired by revolutionary secular nationalism and Nasser's Egypt, engaged in political rivalries with conservative traditionalist Arab monarchies, influenced by Saudi Arabia. The Iranian Revolution of 1979, and the ascension of Ayatollah Ruhollah Khomeini as leader of Iran, is widely seen as the end of this period of internal conflicts and rivalry. A new era of Arab-Iranian tensions followed, overshadowing the bitterness of intra-Arab strife.

Nasser espoused secular pan-Arab nationalism and socialism as a response to the perceived complicity of the Arab monarchies in Western interference in the Arab world. He also opposed the monarchies' support of rentierism and Islamism. Later Nasser embraced the Palestinian cause, albeit within the framework of pan-Arabism. After Egypt's political victory in the 1956 Suez Crisis, known in the Arab world as the Tripartite Aggression, Nasser and his associated ideology quickly gained support in other Arab countries, from Iraq in the east to French-occupied Algeria in the west. In several Arab countries, such as Iraq, North Yemen and Libya, conservative regimes were overthrown and replaced by revolutionary republican governments. Meanwhile, Arab countries under Western occupation, such as Algeria and South Yemen, experienced nationalist uprisings aimed at national liberation. At the same time, Syria, which was already strongly Arab nationalist, formed a short-lived federal union with Egypt called the United Arab Republic. Several other attempts were made to unite the Arab states in various configurations, but all attempts were unsuccessful.

North Yemen (Arabic: اليمن الشمالي, romanized: al-Yaman al-šamāliyya) is a term used to describe the Kingdom of Yemen (1918–1962), the Yemen Arab Republic (1962–1990), and the regimes that preceded them and exercised sovereignty over that region of Yemen. Its capital was Sanaa from 1918 to 1948 and again from 1962 to 1990. Located in the southwestern part of the Arabian Peninsula, the area of the region (Upper Yemen) is 195,000 square kilometers, it used to have a population of about thirteen million people prior to the Yemeni unification. It was bordered to the north by Saudi Arabia, to the south and east by South Yemen, to the west by the Red Sea, and to Bab al-Mandab in the southwest.

North Yemen was admitted to the United Nations on September 30, 1947. In 1962, the country fought a bloody civil war that ended with the abolition of the monarchy and the creation of a republic in 1970. It was one of the predecessor states of the Republic of Yemen, alongside South Yemen, until its eventual unification in 1990.

Abdullah Yahya al-Sallal (Arabic: عبد الله يحيى السلال, romanized: ʿAbd Allāh Yaḥyā as-Sallāl; 9 January 1917 – 5 March 1994) 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.

The President of the Yemen Arab Republic, officially the Chairman of the Republican Council of the Yemen Arab Republic, was the head of state in the former North Yemen from 1962 to 1990. There were six presidents of North Yemen.