Question: Which conflict involving the Mende ethnic group lasted for eleven years?

Context:
Mongeri
Mongeri is a town in Bo District in the Southern Province of Sierra Leone.
 Its population was estimated at 14,273 (2004 census).
 The population of Mongeri is mostly from the Mende ethnic group.
 It is the birthplace of Samuel Hinga Norman, the founder and leader of the traditional Civil Defence Forces (commonly known as the Kamajors).
Gbangbatoke
Gbangbatoke is a small town in Moyamba District in the Southern province of Sierra Leone.
 The town is best known for being the birthplace of two of Sierra Leone's most prominent politicians, Sir Milton Margai and Sir Albert Margai.
 The population of Gbangbatoke is predominantly from the Mende ethnic group, and the Mende language is widely spoken.
Albert Joe Demby
Albert Joe Demby (born 1934 in Gerihun, Kenema District) is a Sierra Leonean politician and a member of the Sierra Leone People's Party.
 He served as the Vice President of Sierra Leone from 29 March 1996 to 25 May 1997, when the administration was overthrown by a military junta.
 After the junta was deposed in 1998, he continued his term until 1999, when he was dropped from vice presidency by Ahmad Tejan Kabbah in favor of Foday Sankoh.
 The vice-presidency was stripped from Sankoh in 2000, and Demby took his place once again.
 Kabbah's term ended in 2002, and Demby was succeeded as Vice President by Solomon Berewa, who had previously served as Minister of Justice and Attorney-General.
 Like Berewa, Joe Demby is from the Mende ethnic group.
 
Shirley Gbujama
Madam Shirley Yema Gbujama (born 1936, as Shirley Macaulay) is a Sierra Leonean politician who served in a number of cabinet positions, including Minister for Foreign Affairs, Minister of Social Welfare, Minister of Tourism and Culture, and Minister of Gender and Children’s Affairs.
 She was one of the most respected and longest-serving cabinet ministers in President Ahmad Tejan Kabbah's government.
 Gbujama belongs to the Mende ethnic group.
Sierra Leone Civil War
The Sierra Leone Civil War (1991–2002) began on 23 March 1991 when the Revolutionary United Front (RUF), with support from the special forces of Charles Taylor’s National Patriotic Front of Liberia (NPFL), intervened in Sierra Leone in an attempt to overthrow the Joseph Momoh government.
 The resulting civil war lasted 11 years, enveloped the country, and left over 50,000 dead.
Septimus Kaikai
Septimus Kaikai (born in Kailahun, Kailahun District) is a Sierra Leonean politician and broadcaster, he served as Minister of Information and Broadcasting from 2002-2007 in former president Ahmad Tejan Kabbah's second term in office.
 Kaikai is a member of the Mende ethnic group and a native of Kailahun District in Eastern Sierra Leone.
Francis Minah
Francis Misheck Minah (19 August 1929 in Sawula, Pujehun District – 1989) was a Sierra Leonean politician.
 Minah earned his law degree from King's College London.
 He returned to Sierra Leone and served in many capacities as Sierra Leone's Minister of Foreign Affairs, Minister of Health, Minister of Justice and Attorney General, under former president Siaka Stevens.
 He was later appointed the Vice President of Sierra Leone under former president Joseph Saidu Momoh administration.
 In 1987, he was falsely accused of plotting a coup against president Momoh.
 Minah was hanged in 1989, following his trial and conviction for alleged involvement in the 1987 coup.
 Minah was a member of the Mende ethnic group.
Civil Defence Forces
The Civil Defense Forces (CDF) was a paramilitary organization that fought in the Sierra Leone Civil War (1991–2002).
 It supported the elected government of Ahmed Tejan Kabbah against the rebel groups Revolutionary United Front (RUF) and Armed Forces Revolutionary Council (AFRC).
 Much of the CDF was made up of the Kamajors group, which is part of the larger Mende ethnic group.
 The Kamajors believed in many magical ways of defending themselves, such as rituals to create bulletproof skin.
Kamajors
The Kamajors were a group of traditional hunters from the Mende ethnic group in the south and east of Sierra Leone (mostly from the Bo district).
 The word ""Kamajor" derived from mende ""kama soh"" meaning traditional hunter with mystical powers, and were originally employed by local chiefs.
Momodu Koroma
Momodu Koroma (born 1956 in Yonibana, Tonkolili District) is a Sierra Leonean politician.
 He is a former Minister of Foreign Affairs and a member of the Sierra Leone Peoples Party (SLPP).
 He became foreign minister in May 2002, as part of a new cabinet appointed following President Ahmed Tejan Kabbah's re-election earlier in the month.
 Koroma had previously been Minister of Presidential Affairs.
 Koroma was born in the small town of Yonibana in the Tonkolili District, his father was from the Temne ethnic group, while his mother came from the Mende ethnic group.
 It is very rare in Sierra Leone to see an inter-ethnic marriages between Sierra Leone's two largest ethnic group the Temne and Mende.

Answer: Sierra Leone Civil War