Tanzania profile - Leaders
President: John Magufuli
Public Works Minister John Magufuli won the 2015 presidential election by a surprisingly large margin over his main challenger and former prime minister, Edward Lowassa.
Nicknamed "The Bulldozer" for his energetic road-building drive and reputation for honesty as minister, Mr Magufuli stood on promises to boost economic performance and, like the opposition, fight corruption.
But he was expected to face stiff resistance on the last count from civil servants from within his own Chama Cha Mapinduzi party, which has run Tanzania since independence.
His other major election pledges - to tackle youth unemployment and establish free primary and secondary education - will to a large degree depend on cautious management of resources.
Mr Magufuli also faces rising political discontent on the island of Zanzibar, where local elections had to be scrapped over vote-rigging allegations shortly before he took office.
His predecessor, Jakaya Kikwete, devoted his two terms as president to continuing the country's broadly successful policy of economic liberalisation.