WAl-Qaeda in the Arabian Peninsula, or AQAP, also known as Ansar al-Sharia in Yemen, is a militant Islamist group primarily active in Yemen and Saudi Arabia that is part of the al-Qaeda network. It is considered the most active of al-Qaeda's branches that emerged after the weakening of central leadership. The U.S. government believes AQAP to be the most dangerous al-Qaeda branch. The group established an emirate during the 2011 Yemeni Revolution, which waned in power after foreign interventions in the subsequent Yemeni Civil War.
WJama'at Ansar al-Shari'a, also known as Ansar al-Shari'a, is a Yemen-based umbrella organization which includes units from several militant Islamic groups of al-Qaeda in the Arabian Peninsula (AQAP). In 2011, AQAP created Ansar Al-Sharia as a Yemen-based affiliate focused on waging an insurgency rather than international attacks on the West. In the view of the International Crisis Group, AQAP is "an internally diverse organisation with varying layers of support among the local population" and many AAS members and allies are not committed to AQAP's international agenda.
WThe Front for the Liberation of Occupied South Yemen (FLOSY) was an Arab nationalist military organization operating in the Federation of South Arabia in the 1960s. As the British tried to exit its Federation of South Arabia colony Abdullah al Asnag created FLOSY. FLOSY attempted to seize power when the British left from another military group operating in South Arabia, the Marxist National Liberation Front (NLF).
WThe Hadhrami League is a movement founded in 2003 under the name of the National Organization for the Liberation of Hadhramaut in Hadhramaut Governorate by Abdullah Saeed Bahaj and called for the self-determination of Hadhramaut residents at home and abroad and the legitimate rights of the People of Hadrami under international laws, foremost of which is the right to Self-determination and the Restoration of its independent State. Hadhramaut was an semi-autonomous British protectorate occupied by South Yemen first in 1967 and again in 1990. After unification between the two Northern and Southern States. The Hadhrami League considers it a "Yemeni occupation".
WThe Hashid is a tribal confederation in Yemen. It is the second or third largest – after Bakil and, depending on sources, Madh'hij – yet generally recognized as the strongest and most influential. According to medieval Yemeni genealogies, Hashid and Bakil were the sons of Jashim bin Jubran bin Nawf Bin Tuba'a bin Zayd bin Amr bin Hamdan. Member tribes of the Hashid Confederation are found primarily in the mountains in the North and Northwest of the country.
WThe Houthi movement, officially called Ansar Allah and colloquially simply Houthis, is an Islamic political and armed movement that emerged from Sa'dah in northern Yemen in the 1990s. The movement was called Houthis because its founder is from the Houthi tribe. They are of the Zaidi school, though the movement also includes Sunnis. Under the leadership of Hussein Badreddin al-Houthi, the group emerged as an opposition to former Yemeni president Ali Abdullah Saleh, whom they charged with massive financial corruption and criticized for being backed by Saudi Arabia and the United States at the expense of the Yemeni people and Yemen's sovereignty. Resisting Saleh's order for his arrest, Hussein was killed in Sa'dah in 2004 along with a number of his guards by the Yemeni army, sparking the Houthi insurgency in Yemen. Since then, except for a short intervening period, the movement has been led by his brother Abdul-Malik al-Houthi.
WThe Islamic State of Iraq and the Levant – Yemen Province is a branch of the militant Islamist group Islamic State of Iraq and the Levant (ISIL), active in Yemen. ISIL announced the group's formation on 13 November 2014.
WThe National Liberation Front or NLF was a Marxist paramilitary organization and a political party operating in the Federation of South Arabia, during the Aden Emergency. During the North Yemen Civil War, fighting spilled over into South Yemen as the British attempted to establish an autonomous colony known as the Federation of South Arabia. Following the exit of the British armed forces, the NLF seized power from its rival, the Arab nationalist Front for the Liberation of Occupied South Yemen (FLOSY). In the aftermath of the Emergency, the NLF reorganized itself into the Yemeni Socialist Party and established a single-party Marxist-Leninist government, known as the People's Democratic Republic of Yemen.
WAl-Qaeda is a transnational extremist Salafist militant organization founded in 1988 by Osama bin Laden, Ayman al-Zawahiri and Abdullah Azzam, and several other Arab volunteers during the Soviet–Afghan War.
WThe Sons of al Mahrah is a Yemeni protest movement that emerged from Al Mahrah Governorate in 2018. It is led by former governor, Sheikh Ali Salem Al-Harizi. The movement protests the "Saudi occupation policy" in the al-Mahrah Governorate and the UAE occupation of Socotra.
WThe Southern Movement, sometimes known as the Southern Separatist Movement, or South Yemen Movement, and colloquially known as al-Hirak, is a political movement and paramilitary organization active in the south of Yemen since 2007, demanding secession from the Republic of Yemen and a return to the former independent state of South Yemen. At present, its most well-known political offshoot, the Southern Transitional Council led by Aidarus al-Zoubaidi, is the de facto leadership across many provinces of the south.