After the initial arrival of the Portuguese, no significant European settlements were established until French colonists and soldiers, under the Huguenot Admiral Nicolas Durand de Villegaignon invaded the region in 1555 to establish the France Antarctique. They stayed briefly on Lajes Island, then moved to Serigipe Island, near the shore, where they built Fort Coligny. After they were expelled by Portuguese military expeditions in 1563, the colonial government built fortifications in several points of Guanabara Bay, rendering it almost impregnable against a naval attack from the sea. They were the Santa Cruz, São João, Lajes and Villegaignon forts, forming a fearsome crossfire rectangle of big naval guns. Other islands were adapted by the Navy to host naval storehouses, hospitals, drydocks, oil reservoirs and the National Naval Academy.