Pierre Nkurunziza, a former Hutu rebel leader, became the first president to be chosen in democratic elections since the start of Burundi's civil war in 1994.
He was selected as president by parliamentarians in August 2005 after his Force for the Defence of Democracy (FDD) won parliamentary elections a few weeks earlier.
He was re-elected in June 2010 presidential polls. The vote was boycotted by the opposition, which complained of fraud in the earlier local elections.
The European Union praised Burundi for holding a peaceful presidential election but criticised the government for limits on political expression. Since 2010 opposition leaders and international observers have complained of increasing attacks and pressure on opposition parties and the media.
Armed groups have made a worrying reappearance, exploiting the chaos in neighbouring DRCongo.
The 2005 vote was one of the final steps in a peace process intended to end years of fighting between Hutu rebels and the Tutsi-controlled army.
A peace agreement between the government and the remaining Hutu rebels was signed in 2006, but broke down after the government rejected rebel demands for power-sharing. A ceasefire with the last major active rebel group, the National Liberation Forces (FNL), was signed in May 2008.
Born in 1964 in Ngozi province, Pierre Nkurunziza trained as a sports teacher. His father, a former MP, was killed in ethnic violence in 1972.
He joined the Hutu rebellion in 1995 and rose through the ranks to become head of the FDD in 2001. He sustained a serious mortar injury during the conflict.
The married father of two is a born-again Christian.