Why There Are So Many Countries Named Guinea

History Matters takes a brief look at why so many countries have the name Guinea, focusing on the origins of the name. The narrator also looks at the history of each of the countries, who laid claim to those countries, and how the nomenclature became formalized due to colonialism.

Guinea, Guinea-Bissau, Equatorial Guinea and Papua New Guinea are all called Guinea to some degree. But what led to this happening? Why are there four modern nations called Guinea?