Before independence from Portugal, Cabo Verde did not have an official flag, and the Portuguese national flag was used. In the late 1960s, a flag for the Portuguese overseas province of Cabo Verde was proposed, consisting of the flag of Portugal with the shield from the provincial arms added to the lower fly. However, this flag was never adopted.
The original national flag of Cabo Verde was introduced on independence in 1975 and was based on the flag of the African Party for the Independence of Guinea and Cabo Verde (PAIGC). It used the common African colors of red, green and yellow, and was identical to the flag of Guinea-Bissau except for the proportions and the charge in the hoist-side stripe. Their similarity evoked the plans to unite both countries, which, however, were abandoned shortly after independence. Guinea-Bissau gained independence on 10 September 1974.