Léon Kengo wa Dondo

After serving as his country's ambassador to Belgium, Kengo served as Prime Minister for the first time from 1982 to 1986, appointing able technocrats to important positions, such as Munga Mibindo, President Delegate General of the National Electrical Utility. He then served as foreign minister from 1986 to 1987 and as Prime Minister again from 1988 to 1990. During the early 1990s Mobutu allowed a transitional parliament to be set up, and Kengo was chosen Prime Minister by it in 1994 as a candidate in an attempt to neutralise the challenge from the popular opposition politician Étienne Tshisekedi. He expelled members of the Lebanese community from Zaire for alleged involvement in the illegal trade of conflict diamonds, though the credibility of such actions is perhaps challenged by the fact that trade in conflict diamonds from Angola had long been essential to the survival of the Mobutu regime, in which Kengo had been such an important figure.

Shortly after the beginning of the Congo civil war, in December 1996, Kengo became the leader of a crisis cabinet which sought to defeat the rebellion of Laurent Kabila. He was undermined by many Mobutu supporters because of his Tutsi origins, as Kabila's rebels were allied with the Tutsi governments of Rwanda and Burundi. As Kabila's armies advanced through the country, Kengo was also criticized for not conducting the war very well. He announced his resignation in March 1997 and left office in April 1997. The Mobutu government fell a month later, and Kengo retired from politics. In 2003, he was charged with money laundering in Belgium.[8][9]

Charles Mwando Nsimba addressing the Senate with Kengo presiding

Following his return to the Democratic Republic of the Congo, Kengo backed Jean-Pierre Bemba in the 2006 presidential election; Bemba was defeated by President Joseph Kabila in the second round of the election.[10] Kengo was then elected as a Senator from Équateur province in January 2007.[11] On 11 May 2007, Kengo was somewhat unexpectedly elected as President of the Senate, defeating Léonard She Okitundu, the candidate of the majority coalition, the Alliance of the Presidential Majority. Kengo, who was an independent candidate, took 55 votes against 49 for Okitundu.[10][11] On 21 January 2015 during the 2015 Congolese protests he met with American, Belgian, British and French diplomats who urged him to either suspend debate and voting on the election modifying law or to remove its controversial provisions.[12] He served as Senate president until 5 April 2019.[3]