Yar'Adua, Umaru Musa (ōmäˈrō mōˈsä yär ädōˈä) [key], 1951–2010, Nigerian politician, president of Nigeria (2007–10). Born into a family active in Nigerian political and military affairs, he was trained as a chemist at Ahmadu Bello Univ., Zello (B.Sc, 1975; M.Sc. 1980). He then taught chemistry and later managed (1983–89) the family farming business. Yar'Adua entered political life in the late 1970s as a member of the leftist People's Redemption party and later joined the Social Democratic party. As a member of the People's Democratic party (PDP), he was elected governor of the state of Katsina in 1999 and reelected in 2003. During his tenure, the state saw economic gains as well as improvements in its medical system, agriculture, and electrification. It also adopted (2000) Islamic law (sharia). Yar'Adua, who had not previously been prominent in national Nigerian politics, became the PDP's presidential candidate in 2006 when President Olusegun Obasanjo engineered his selection. He won the presidency in 2007 after an election that was almost universally condemned as fraudulent. Although his administration appeared to be marked by a greater respect for the law than his predecessor's, his early years in office were marked largely by unfulfilled promises to curb corruption and modernize the oil industry. In 2009 he had some success in bringing peace to the strife-torn but oil-rich Niger Delta region, but by early 2010 his continued absence abroad (from Nov., 2009) for medical treatment threatened Nigeria with a political crisis over his failure to transfer executive powers to Vice President Goodluck Jonathan. In February, however, the National Assembly voted to name Jonathan acting president. Jonathan continued as acting president after Yar'Adua returned late that month and succeeded him after he died in May, 2010.