Uppsala universitet

In the 19th century the southern part of Yemen became a British colony whereas the northern part of country came under the rule of the Ottoman Empire. Upon the end of the First World War North Yemen gained independence, while South Yemen remained under British administration until 1967. Finally, in 1990 the two states agreed to reunify and formed the Republic of Yemen.

The history of independent North Yemen was marked by several violent power struggles. In 1918, Imam Yahya Mahmud al-Mutawwakil took over power from the Ottomans. His authoritarian theocratic rule caused widespread dissatisfaction among the population that culminated in his assassination by reformers in 1948. However, the same year, an opposition coalition led by Imam Yahya's eldest son Ahmed succeeded in overthrowing the new government in a short intra-state conflict and assumed power. When Imam Ahmed died in 1962, his son Muhammad al-Badr became Imam, but was ousted within a week. An intrastate conflict ensued between the Royalist - the supporters of the Imam - and the new government that had established a republic in North Yemen. The conflict lasted until 1970, when the two sides agreed on power-sharing.

In colonial South Yemen pro-independence movements emerged. The NLF (National Liberation Front) and the FLOSY (Front for the Liberation of Southern Yemen) fought the British colonial power from 1964 to 1967. As a result of the conflict, the British rulers transferred the power to the most powerful of the groups, the NLF, and granted independence to South Yemen in 1967.

The relations between independent socialist South Yemen and western-oriented North Yemen were strained at times and common border conflicts occurred in 1972 and 1978-1979. South Yemen also financially supported an opposition coalition in North Yemen, the leftist National Democratic Front, which fought the government in an intrastate conflict from 1980 to 82. In South Yemen, a faction of the ruling Yemenite Socialist Party engaged in a short intrastate war in 1986. The conflict brought to power a government that paved the way for reunification with North Yemen in 1990.

About four years after reunification, a secessionist movement, the Democratic Republic of Yemen, unsuccessfully attempted to re-establish independent South Yemen. It was quickly defeated by the government.

Since 2009, the government has been engaged in an armed conflict over government with the al-Qaida in the Arabian Peninsula (AQAP).

From 1972 to 1975, South Yemen provided secondary warring support to the PFLOAG (Popular Front for the Liberation of the Arabian Gulf) against the government of Oman. In 1979, South Yemen received secondary warring support from Ethiopia in the interstate conflict with North Yemen. In 2010-2013, Yemen received secondary warring support from the USA in the intrastate conflict over government with AQAP.

Since 1946 Yemen has experienced the extra-state, interstate, intrastate, non-state and one-sided categories of UCDP organised violence.