Born into the Esangui clan in Acoacán, Obiang joined the military during the colonial period, and attended the Military Academy in Zaragoza, Spain. He achieved the rank of lieutenant upon the election of Francisco Macías Nguema. Under Macías, Obiang held various jobs, including governor of Bioko, head of the Black Beach Prison, and leader of the National Guard.[citation needed]

He deposed Francisco Macías on 3 August 1979 in a bloody coup d'état. Macías was placed on trial for his activities over the previous decade and sentenced to death. His activities had included the genocide of the Bubi. He was executed on 29 September 1979 by firing squad.[citation needed]

Obiang declared that the new government would make a fresh start from the repressive measures taken by Macías' administration. He inherited a country with an empty treasury and a population that had dropped to a third of its 1968 level, with about 50% of the former 1.2 million inhabitants having moved either to Spain or to neighboring African countries, or being murdered during the dictatorship of Obiang's predecessor. He formally assumed the presidency in October 1979.

A new constitution was adopted in 1982; at the same time, Obiang was elected to a seven-year term as president. He was reelected in 1989 as the only candidate. After other parties were permitted to organize, he was reelected in 1996 and 2002 in elections condemned as fraudulent by international observers.[citation needed]

Obiang's regime retained clear authoritarian characteristics even after other parties were legalized in 1991. Most domestic and international observers consider his regime to be one of the most corrupt, ethnocentric, oppressive and undemocratic states in the world. Equatorial Guinea is now essentially a single-party state, dominated by Obiang's Democratic Party of Equatorial Guinea (PDGE). In 2008 American journalist Peter Maass called Obiang Africa's worst dictator, worse than Robert Mugabe of Zimbabwe. The constitution grants Obiang wide powers, including the power to rule by decree. Nonetheless, Obiang has far less power than Macías, and for the most part his rule has been considerably milder. Notably, there have been none of the atrocities that characterized the Macías era.[citation needed]

All but one member of the 100-seat national parliament belong to the PDGE or are aligned with it. The opposition is severely hampered by the lack of a free press as a vehicle for their views. Around 90% of all opposition politicians live in exile, 550 anti-Obiang activists have been jailed unfairly, and several killed since 1979.[citation needed]

In July 2003, state-operated radio declared Obiang to be a god who is "in permanent contact with the Almighty" and "can decide to kill without anyone calling him to account and without going to hell." He personally made similar comments in 1993. Despite these comments, he still claims that he is a devout Catholic and was invited to the Vatican by John Paul II and again by Benedict XVI. Macías had also proclaimed himself a god.

Obiang has encouraged his cult of personality by ensuring that public speeches end in well-wishing for himself rather than for the republic. Many important buildings have a presidential lodge, many towns and cities have streets commemorating Obiang's coup against Macías as well as there being a penchant among the population to wear clothes with his face printed on them.[citation needed]

Like his predecessor and other African dictators such as Idi Amin and Mobutu Sese Seko, Obiang has assigned to himself several creative titles. Among them are "gentleman of the great island of Bioko, Annobón and Río Muni." He also refers to himself as El Jefe (the boss).[citation needed]

In similar fashion to Idi Amin, Obiang has purportedly allowed rumors that he is a cannibal to circulate. Fictional rumors on cannibalism had been used for centuries among the Fang people of Central and West Africa to make opponents fear them, of which Obiang is a descendant. Many testimonies of former residents of Equatorial Guinea, before and during the civil unrest, indicate that cannibalism had been applied as a tool of psychological warfare.