He was born Lúcio Matias de Sousa Mendes in the town of Tarrafal in the island of Santiago's north in the final decade of Portuguese rule.

As a composer, he was a member of SACEM (Societé française des Droits d'auteur) with compositions that Cesária Évora and other Cape Verdean artists recorded.

He composed at a request of the Porto European Culture Capital on the soundtrack of the play Adão e as Sete Pretas de Fuligem, performed by João Branco.

In 2009, he wrote a novel titled Testamento (Testament) published by Dom Quixote, his recent novel won the Carlos de Olvieira Award and was a bestseller in Portugal.

After the 2016 general election, Álvaro Anibal Barbosa Vicente succeeded Mário Lúcio Sousa as culture minister.