Benin, a country in West Africa has two capital cities, Port-Novo and Cotonou. In Benin, Porto-Novo has always been the official capital, even back when Benin was a French colony. Despite this, Cotonou has always been the city that has housed the country's government. This trend of these two cities playing these roles has continued even after Benin achieved its independence in 1970.
The reason that Bolivia has two capitals cities goes back to the Federal Revolution of 1899. The Liberal Party was mostly backed by tin mine families in La Paz, while the ruling conservative party was mostly backed by silver mine families in Sucre. The Liberals overthrew the Conservatives, and one of their demands was to move the official capital to La Paz. Eventually, there was an agreement to keep the official capital in Sucre, while La Paz would get more power by being where the executive and legislative seats of the government would be located.
The reason that Chile has two capitals is fairly recent and goes back to the end of the reign of dictator and president Augusto Pinochet. Santiago has always been the official capital of Chile, going all the way back to colonial times. Towards the end of Pinochet's regime in 1990, it was decided to move the National Congress of Chile from Santiago to the city of Valparaiso both as a gesture of decentralization and an effort to appease the public to stay in power.
The reason that Georgia has two capital cities is that it can distribute its government's functions between the two cities and also honor the past of both the cities. The city of Tbilisi is the official capital of the country, and it is here where the executive functions of the government are performed. The city of Kutaisi, on the other hand, is the legislative capital of the government. The Parliament of Georgia is also located here. Both Kutaisi and Tbilisi have storied pasts as being the capitals of past kingdoms and dynasties that have come and gone in Georgia's past, which is why they are both honored by having a role in the government.
Tegucigalpa had been the capital of Honduras since 1880 when it was designated as the capital. The catalyst for Honduras' change from a single capital to a two capital country then started in 1937. That year the 1936 Honduran Constitution was changed to combine the capital of Tegucigalpa and its sister city of Comayagüela into a Central District. In 1982 when Honduras's current constitution was established it was decreed that the Municipality of the Central District would serve as the capital, meaning that both cities where now the capital since they made up the Central District.
Ivory Coast (Côte d'Ivoire)
The city of Abidjan was declared the capital of the Ivory Coast in 1933 when it was still under French rule as a colony and stayed the capital after the country became independent. However, the reason that the Ivory Coast has two capitals is fairly recent and is associated with the country's first president. After twenty-three years in office, President Félix Houphouët-Boigny decided to move the official capital of the country from Abidjan to his hometown of Yamoussoukro. Houphouët-Boigny did this to spur development in the center of the country and to uplift his hometown. Despite this change, most of the embassies and government institutions remain in Abidjan.
The reason that Malaysia has two capitals is recent and has to do with overcrowding and political congestion in the official capital of Kuala Lumpur. The government of Malaysia realized that this was a problem and decided to take action. They started working on designing a planned city to specifically handle the government's federal level administrative functions. The city of Putrajaya was established in 1995 and by 1999 was ready for the seat of government and the judiciary to move to the city.
The reason that Montenegro has two capitals is because it is a way to honor its past history. Podgorica is the official capital of Montenegro and where all of the country's government functions take place. The city of Cetinje has the honor of having the status of being the historical capital of the country. This is to honor Cetinje's role as the former capital of Montenegro and as the cultural center of the country.
Unlike most countries on this list the Netherlands has always had two capitals. Amsterdam has been the official and constitutionally mandated capital of the country since 1814 when the new kingdom of the country was formed following freedom from French rule. However, The Hague has been the seat of basically all government functions for the country since 1588, only some years after the establishment of the Republic of the United Netherlands. The Dutch have always had a separate official capital and a capital for government functions before most other countries though to try this.
The reason that South Africa is the only country in the world with three different official capitals goes back to the 1910 unification of South Africa. At this point in time the four founding provinces of South Africa, Cape Colony, Orange River Colony, Transvaal Colony and Natal Colony, could not decide a capital city that could be shared by all. They eventually came to an agreement where they would each have a capital: Cape Colony (Cape Town), Orange River Colony (Bloemfontein) and Transvaal Colony (Pretoria). Each of these capitals would administrate a different branch of the government. The capital city of the Natal Colony, Pietermaritzburg, was given financial compensation as part of the agreement for not being a capital.
South Korea is the most recent country on the list to adopt having two capitals. Seoul has been the official capital of South Korea even back in historical times but in 2003 the government started looking at moving some government functions elsewhere to reduce political congestion. After some political back and forth it was agreed in 2007 that a new special administrative district would be created to house these government functions. Finally in 2012 Sejong City was officially opened to the administrative capital of the country and many government agencies have relocated there.
A few decades after gaining its independence, the government of Sri Lanka came to the conclusion that the capital of Colombo became too political congested. In 1977 the government decided on moving the national legislature to a suburb of Colombo, Sri Jayawardenepura Kotte. A few years later in 1982 the country's Parliament moved to Sri Jayawardenepura Kotte, and it has since become the legislative capital.
Swaziland has always had two capitals. The city of Lobamba has always been considered the traditional seat of the kingdom and is where the rulers of the country live. It is also the city where the countries Parliament meets. Mbabne is the administrative capital of the country that handles all of the other government functions outside of Parliament.
Prior to 1973 Dar es Salaam was the official capital of the country of Tanzania. However, that year the government decided to move the capital from Dar es Salaam to the city of Dodoma due to its centralized location. Despite this change the National Assembly delayed moving to Dodoma until 1996 and most of the government and embassies stay in Dar es Salaam instead of moving to Dodoma.
Western Sahara has two capitals due to its complicated status as a disputed territory between the country of Morocco and the partially recognized state of Sahrawi Arab Democratic Republic, who both claim Western Sahara as their land. The city of Laayoune is the capital of the Laâyoune-Sakia El Hamra region that is claimed by Morocco and is under the supervision of the United Nations. Tifariti is the capital of the proclaimed Sahrawi Arab Democratic Republic since their government moved there in 2011 from their previous capital of Bir Lehlou.