Zaire, now known as the Democratic Republic of Congo, had French as its official language from its independence in 1960 until 1971.
In 1971, President Mobutu Sese Seko changed the name of the country to Zaire and implemented a policy of "authenticité", aiming to distance the country from its colonial past. As part of this policy, he changed the official language from French to Swahili, which was renamed "Kiswahili".
This change was primarily symbolic, as French continued to be widely used in government, education, and commerce. However, Kiswahili became the official language of the country.