History of the Comoros (1978–89)
The Comoros is an island nation in the Indian Ocean, located off the eastern coast of Africa. France first established colonial rule in the Comoros in 1841. Agreement was reached with France in 1973 for the Comoros to become independent in 1978. On July 6, 1975, but the Comorian parliament passed a unilateral resolution declaring independence. The deputies of Mayotte, which remained under French control, abstained. Referendums on all four of the islands excluding Mayotte showed strong support for independence. Ahmed Abdallah proclaimed the Comoros' independence on September 5, 1975 and became its first president.
Geology of the Comoros
The volcanoes in the Comoros date to the recent past of the Pliocene, Pleistocene and Holocene period. 
The oldest volcano on the chain is 7.7 million years old, on Mayotte. Volcanoes are older further east. Anjouan is 3.9 million years old and Moheli is five million years old. Grande Comore is the youngest at only 10,000 years old. Some geologists have proposed that the Comoros is an example of one of 11 primary mantle plumes worldwide.