Newly appointed Zimbabwean Vice President Emmerson Mnangagwa smiles at the headquarters of President Robert Mugabe's ZANU-PF in Harare, Dec. 10, 2014. Reuters/Philimon Bulawayo

Zimbabwe’s new Vice President Emmerson Mnangagwa was sworn into office on Friday, making him the heir apparent to 90-year-old President Robert Mugabe. Mugabe, who has ruled Zimbabwe since its independence from Britain in 1980, anointed Mnangagwa, 68, after a messy political battle with former Vice President Joice Mujuru. Mujuru’s sudden ouster following 10 years of service at the ruler’s side has been widely credited to Mnangagwa, according to the South African news site News24.

Mnangagwa’s promotion to the second-highest office in Zimbabwe comes after a long career in the country’s ruling Zimbabwe African National Union -- Patriotic Front (ZANU-PF) Party, most recently as its justice minister. Following the party’s formation in the early 1960s, Mnangagwa led a group of its members to China for military training to bolster its independence struggle, reported the BBC. Zimbabwe, which was known as Rhodesia at the time, experienced tumult as liberation groups organized against the British, and Mnangagwa was sentenced to death in 1965 for blowing up trains and killing a white farmer. Though his sentence was later overturned, Mnangagwa was reportedly tortured during his time in prison.

While in jail, Mnangagwa met Mugabe, whom he linked up with politically following his release in the early 1970s."That's where the bond between the two developed. He looked up to Mugabe as his father," ZANU-PF MP Joram Gumbo told the BBC. Mnangagwa was elected by the party to be Mugabe’s special assistant in 1977, which gave him enormous power in the fledgling party that later became Zimbabwe’s main political force.

Mnangagwa also played a crucial role in Mugabe’s crackdown against opposition forces in the 1980s. This crackdown, which became known as Gukurahundi, resulted in the deaths of thousands, according to the Associated Press, and was condemned internationally.

The close relationship between Zimbabwe’s leader and Mnangagwa hit some turbulence in late 2004, when Mugabe stripped him of his titles following a disagreement over unofficial meetings to rally support for the vice presidency. The fractures between the two were seemingly mended a few years later when Mnangagwa reportedly masterminded ZANU-PF’s political campaign around the country’s disputed 2008 elections, according to the BBC. During this time, Mnangagwa was accused of planning the violence that left hundreds dead.

Nicknamed “the crocodile,” Mnangagwa is known for his political cunning and is thought to have teamed up with first lady Grace Mugabe in the effort to oust Mujuru as the president’s second-in-command. As Africa’s oldest head of state, Mugabe has been increasingly focused on securing his party’s fortunes following his rule, according to the AP, and recently purged several ministers from within ZANU-PF. Mnangagwa’s elevation leaves him poised to succeed Mugabe.