Carlos Diego Mesa Gisbert (born August 12, 1953) became the President of Bolivia on Friday, October 17, 2003. As vice president under the previous president of Bolivia, Gonzalo Sánchez de Lozada, Mesa assumed the post when extensive protests and strikes shut down Bolivia in a bitter dispute known as the Bolivian Gas War, forcing Sánchez de Lozada to resign and flee the country.
Before entering politics, Mesa was a historian and a journalist in radio, television and newspapers. He is a member of the Bolivian History Academy.
Despite his inexperience in the political arena, Mesa's star rose quickly in the Sánchez de Lozada administration. In September 2003, he was invited to address the UN General Assembly, where he warned:
Democracy is in danger in Bolivia as the result of legitimate pressures from the poor. We cannot generate economic growth and well-being for a few and then expect that the large majorities that are excluded will watch silently and patiently. We poor countries demand that our products be admitted into the markets of rich countries in adequate conditions. 
As the gas conflict escalated, Mesa became increasingly unhappy with the government's heavy-handed repression of the protests, which left an estimated 70 people dead. He withdrew his support for Sánchez de Lozada several days before the latter's resignation, saying: "I cannot continue to support the situation we are living through."
Mesa's first challenge will be to return peace and stability to Bolivia and address the grievances of the country's huge, marginalized indigenous population.
Bolivia's next presidential elections were scheduled for 2007, but Mesa was quick to point out that his administration was transitional and that he did not intend to complete Sánchez de Lozada's term in office. He also promised to hold a binding referendum on the gas export plan.
Gonzalo Sánchez de Lozada
Presidents of Bolivia