Who is Riek Machar, South Sudan's embattled vice president?

(Reuters) -The reported house arrest of Riek Machar, the former bush rebel leader who became South Sudan's First Vice President, marks the latest turn in the turbulent relationship with his rival, President Salva Kiir, after a five-year civil war.

The two men, now in their early 70s, launched a conflict in 2013 that led to hundreds of thousands of deaths, as the newly independent nation fractured along ethnic lines with Kiir leading largely Dinka forces against Nuer fighters allied with Machar.

That war ended with a peace deal in 2018 but their bitter rivalry cast a long shadow over the agreement's implementation and ethnic fissures have regularly resurfaced in recent years, sparking fears of a renewed conflict.

Clashes erupted this year in Upper Nile State between South Sudanese troops and the White Army, a predominantly Nuer militia that fought alongside Machar's forces in the civil war.

The government this month accused Machar's SPLM-IO party of collaborating with the militia, in an echo of the tensions that saw Kiir sack Machar as vice president in 2013 and led to the outbreak of war. The SPLM-IO has denied ongoing links with the White Army.

Between 2013 and 2018, fighting between troops loyal to both men shut down oil fields, forced a third of the country's population from their homes and killed more than 400,000.

FIGHT FOR INDEPENDENCE

Machar's role in the south's fight for independence from Sudan had always been controversial. 

In 1991, he fell out with John Garang, leader of the pro-independence SPLA rebel movement, leaving his post as a commander in the group after a disagreement.

The same year, Machar was blamed for an ethnic massacre of Dinka people in Bor carried out by Nuer fighters loyal to him.

Machar was seen by some former rebel comrades as a traitor because of the 1997 Khartoum peace accord he signed with the Sudanese government, which rewarded him with the positions of vice-president of Sudan and chairman of the coordinating council that technically ruled the south. 

Machar rejoined the SPLA in 2002, and after a 2005 peace deal that ended civil war and established southern autonomy, he became vice-president of the South, retaining the position after South Sudan's independence in 2011 until his sacking in 2013.

DISMISSAL

Machar's dismissal was one of the factors that sparked a return to civil war in December 2013. At the time Kiir accused him of attempting a power grab, which Machar denied. An African Union Commission of Inquiry found no basis for the coup allegation.

Several peace deals failed, including one in 2015 that briefly halted hostilities but fell apart after Machar returned to Juba the following year.

When the civil war ended, he struck a conciliatory note.

"I want to assure you that we will work collectively to end your long suffering," Machar told South Sudanese when he was sworn in as vice president in the unity government in 2020.

Machar trained as an engineer at the University of Khartoum, studied at Scotland's University of Strathclyde and holds a PhD from the University of Bradford in England.

In 1991, he married a British aid worker, Emma McCune, and their life together in the war-torn south Sudanese bush became the subject of newspaper articles and a book.

McCune died aged 29 in a car crash in Nairobi in 1993. Machar's second wife, Angelina Teny, has previously served as defence minister and was appointed interior minister in 2023.

In an apparent attempt to boost his stature as a leader of the Nuer, South Sudan's second largest tribe after the Dinka, Machar has kept in his possession a ceremonial stick once carried by a famous Nuer prophet, Ngundeng Bong.

The "dang" stick, made from the root of a tamarind tree and decorated with copper wire, was looted by British colonial troops before being returned to South Sudan in 2009 by British academic Douglas Johnson. 

(Reporting by George Obulutsa; Writing by Ammu Kannampilly and Ayen Deng Bior; Editing by Giles Elgood and Ros Russell)