History of Rio de Janeiro

Several years after the Portuguese first explored Brazil, French traders in search of pau-brasil (a type of brazilwood) reached the rich area extending from the Cape Frio coast to the beaches and islands of Guanabara Bay, the economic and, above all, strategic importance of which was already well-known.

Overview
In 1555, one of the islands of Guanabara Bay, now called Villegagnon Island, was occupied by 500 French colonists under admiral Nicolas Durand de Villegaignon. Consequently, Villegagnon built Fort Coligny on the island when attempting to establish the France Antarctique colony, which the French called Henriville in honor of Henry II of France.