The Republic of Independent Guyana, in French La République de la Guyane indépendante, commonly referred to by the name of the capital Counani (rendered Cunani in Portuguese by the Brazilians), was a short-lived independent state in the area which was disputed by France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 (as part of French Guyana) and Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 in the late nineteenth century. The state was founded by French settlers and existed from 1886 to 1891. The territory of the former state of Counani is now located in the Brazilian state of Amapá

Amapá

Amapá is one of the states of Brazil, located in the extreme north, bordering French Guiana and Suriname to the north. To the east is the Atlantic Ocean, and to the south and west is the Brazilian state of Pará. Perhaps one of the main features of the state is the River Oiapoque, as it was once...

.

Sources

L'État libre de Counani ou l'expression d'une Guyane indépendante. An account of the two Republics of Counani and some of its postage stamps "Annales d'hygiène et de médecine coloniale, Tome quatrième" (1901), about the sanitary situation in Counani, pp. 121 to 128 : p. 121, p. 122, p. 123, p. 124 (with a map of the territory revendication), p. 125, p. 126, p. 127, p. 128. http://www.crwflags.com/fotw/flags/br_cunan.html