What was Mauritania renamed to?

Mauritania remained as Mauritania and has not been renamed.

When did it gained independence?

Mauritania gained independence from France on November 28, 1960.

Who was the first PM of Mauritania?

The first Prime Minister of Mauritania was Moktar Ould Daddah, who served as Prime Minister from 1957 until Mauritania gained independence in 1960. He then went on to become the first President of Mauritania after independence.