World's longest-serving leaders - Top 20

With the passing of President Lansana Conte of Guinea this week (who was #12 of the top 20 longest-serving leaders), we have revised the list to reflect this reality. Also revised is the socio-economic data for each country based on the latest data available from World Economic Forum and CIA World Facts. For more detaled listing of World's longest-serving leaders, click here.

1. Prime Minister Hassanal Bolkiah (Brunei, since 1967)
2. President El Hadj Omar Bongo Ondimba (Gabon, since 1967)
3. Colonel Muammar Gaddafi (Libya, since 1969)
4. Prime Minister Qaboos bn Said al-Said (Oman, since 1970)
5. Prime Minister Khalifa bin Salman al-Khalifa (Bahrain, since 1971)
6. President Ali Abdallah Saleh (Yemen, since 1978)
7. President Teodoro Obiang Nguema Mbasogo (Equatorial Guinea, since 1979)
8. President Jose Eduardo dos Santos (Angola, since 1979)
9. President Robert Gabriel Mugabe (Zimbabwe, since 1980)
10. President Hosni Mubarak (Egypt, since 1981)
11. President Paul Biya (Cameroon, since 1982)
12. Prime Minister Samdech Hun Sen (Cambodia, since 1985)
13. President Yoweri Museveni (Uganda, since 1986)
14. King Mswati III (Swaziland, since 1986)
15. President Blaise Compaore (Burkina Faso, since 1987)
16. President Zine el Abidine Ben Ali (Tunisia, since 1987)
17. Supreme Leader Ayatollah Ali Hoseini-Khamenei (Iran, since 1989)
18. President Islom Karimov (Uzbekistan, since 1989)
19. President Omar Hassan Ahmad al-Bashir (Sudan, since 1989)
20. President Nursultan Nazarbayev (Kazakistan, since 1990)