Angolan President Joao Lourenco was voted in as leader of the ruling MPLA party on Saturday, as former president Jose Eduardo dos Santos stepped down after dominating the country's politics for nearly four decades.Having served as president since August 2017, Lourenco secured an overwhelming 98.59% of 2 951 delegates' votes to become party president."With the strength of the past and the present we build the future, we can correct what is wrong," Lourenco told delegates at the Popular Movement for the Liberation of Angola (MPLA)'s sixth extraordinary congress.The passing of the baton between the two men is the climax of a handover marked by barely disguised friction and new policies challenging dos Santos's legacy and Lourenco hinted strongly at a need to leave much of that legacy behind."Comrades, we are all aware that we will only build a better future if we have the courage to really correct what is wrong - corruption and nepotism, flattery and impunity that have taken place over the last few years in our country," said Lourenco."Today, with my head up, I leave and pass on the baton to comrade Joao Lourenco," dos Santos had earlier told crowds at the ruling party headquarters in Luanda, the oil rich southern African nation's capital.'Bumpy transition' Liberation war veteran dos Santos, 76, did not seek re-election in the August 2017 polls and handed over power to his defence minister Lourenco, 64.But he stayed on at the helm of the party, where much of the real power is seen to be vested.On Saturday, however, "Comrade Number One" finally relinquished MPLA control to Lourenco and admitted to some mistakes while in office."There is no human activity free from mistakes and I assume that I have committed them as well," dos Santos said. "The stepping down of Jose Eduardo dos Santos as MPLA president is an important watershed moment," said Alex Vines, an Angola expert at the Chatham House think-tank in London."It's been a bumpy transition with a bit of tug-of-war over power between (them)."By choosing a successor from within his own regime, dos Santos had thought he would be assured a peaceful handover.He had earlier given control of strategic sectors of the economy to close confidants -- including the state oil giant to his daughter Isabel.Dos Santos also appointed loyalists to head the country's security forces.A purge of the old guard But Lourenco quickly moved to assert his authority after being elected president last year, beginning to dismantle his predecessor's empire.On the premise of rebooting the listless economy, Lourenco deposed Isabel from the top job at Sonangol as well as her half-brother Jose "Zenu" Filomeno from the leadership of Angola's sovereign wealth fund.Filomeno has since been charged with misappropriating public funds while Isabel faces several graft investigations.Many of dos Santos's acolytes have been purged from the highest echelons of Angolan public life including the army and police chiefs as well as executives at state-owned companies.The clear-out created ructions at the top of the state and the party.In recent months, the two men and their staffs have sought to make amends and smoothe the way to the final handover.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook"Everything is going normally, there hasn't been any turbulence," said Luzia Ingles, secretary general of the party's women's league.But the fissure between the two men had come close to breaking point.Dos Santos had originally proposed stepping down from the party leadership by April 2019 - but Lourenco insisted it must be Saturday."Lourenco is already entirely autonomous as shown by his sacking of the dos Santos children - all of the country's sectors have been purged," said Benjamin Auge, an analyst at the French Institute for International Relations.Since his election, Lourenco - dubbed "JLo" - has enacted sweeping reforms of the oil sector, the country's leading source of revenue, with the aim of reassuring investors.But the new president faces chronic unemployment, sluggish growth and alarming deficits have dogged Africa's second-largest producer of crude.Highlighting the impending storm, Angola has said it will seek a $4.5bn loan from the International Monetary Fund.