The Republic of the Congo, also known as Congo-Brazzaville to differentiate it from the much larger Democratic Republic of the Congo, has its roots in 1880 when Italo-French explorer Pierre Savorgnan de Brazza founded Brazzaville at the northern bank of the Congo river exactly opposite to where King Leopold II of Belgium founded Léopoldville, present-day Kinshasa.
The French raced to settle the colony preventing Leopold to include the north bank of the Congo River to his Free State. Earlier, the Portuguese had never bothered to colonise the mainland and only had a stronghold at coastal Cabinda, presently an Angolan exclave. The new French colony was named Moyen Congo or Middle Congo and was included into French Equatorial Africa in 1910.
In 1911 the French ceded large parts of Middle Congo to Germany in return for the Germans letting go of their interest in Agadir, Morocco, during the Morocco Crisis. The Germans thus expanded Kamerun with what they called Neukamerun (New Cameroon). This German presence would only last a few years as by 1916 all German African possessions were lost to the Allies. France restored the pre-1911 borders and took control of Cameroon separately as a League of Nations mandate.
The Republic of the Congo was granted independence in 1960, after which it became a socialist country aligned with communist states, although France never cut its diplomatic ties. From 1972 to 1992 the official name was République Populaire du Congo, or People's Republic of the Congo. After free elections in 1992 the name was changed dropping 'Populaire'. Politically unstable, the country has fought two civil wars in the last two decades with Angolan, Cuban, French and Congolese intervention.
The Republic of the Congo never had its own currency but used the French Equatorial Franc and successors from 1948. There are however 100 & 500 CFA coins with individual country names and these are listed under Republic of the Congo. They are pretty hard to find, especially the 500 Francs. There is also a Central African States 500 Francs with letters A to E marking the member state. Congo corresponds to C:
https://en.numista.com/catalogue/pieces3511.html
https://en.numista.com/catalogue/congo-brazzaville-1.html
