Until now, the second place was held by Zimbabwe’s Robert Mugabe who had ruled the country since independence in April 1980 but who resigned on Tuesday.
Mugabe began his 37-year reign first as prime minister, then as president. At 93, he was also the oldest head of state in power in the world.
Here is a rundown:
– More than 30 years –
– Obiang has been leader of the tiny, oil-rich Equatorial Guinea for 38 years.
He came to power in a coup on August 3, 1979, ousting his own uncle, Francisco Macias Nguema, who was shot by a firing squad. He was re-elected to a fifth seven-year term in 2016.
– In Cameroon, Paul Biya has 35 years under his belt. He became president on November 6, 1982 after serving seven years as prime minister.
– Congolese President Denis Sassou Nguesso has spent 33 years in office, but not in one go. He first served from 1979 to 1992 and then came back to run the country in 1997 at the end of a civil war. Sassou Nguesso was re-elected in March 2016 and could run again when his current term expires.
– In Uganda, Yoweri Museveni has been in power for more than 31 years. He took office in January 1986 after winning the war that ousted Idi Amin Dada, with help from neighbouring Tanzania.
He was elected to a fifth term in February 2016 despite allegations of fraud.
– King Mswati III of Swaziland is Africa’s last absolute monarch. He acceded to the throne of the tiny southern kingdom in April 1986 and has ruled for more than 31 years.
– More than 20 years –
– In Sudan, Omar al-Bashir has ruled for 28 years since he staged a successful coup in June 1989.
– Chad’s leader Idriss Deby took over the north-central African nation in December 1990, giving him 27 years in power. Deby won a disputed fifth term in April 2016.
– Eritrea’s head of state Issayas Afewerki has been around since 1993, giving him 24 years in power.
– Previous records –
Ethiopian emperor Haile Selassie holds the record for the longest time in power on the African continent. After reigning for 44 years, he was ousted in 1974.
Libya’s Moamer Kadhafi, who ruled with an iron fist for nearly 42 years, was slain on October 20, 2011, after a protest movement turned into an armed conflict.
Gabon’s Omar Bongo Ondimba died in June 2009 after more than 41 years in power.
Angola’s Jose Eduardo dos Santos stepped down on September 26, 2017, after leading his country for 38 years.