sentences:  The river had belonged to Spain until then, by virtue of the Treaty of Madrid, but the Spanish wanted to recover at all costs the lost positions, neglecting the Treaty of 1750.In 1766 they left the fort and went to the river Napo, facing the difficulties of communication with the Papal Post Office and the tropical climate.In 1768 the position, abandoned by the Spanish, was taken by soldiers of the Portuguese captain, who by order of the Governor of the colonial state of the Grão-Pará and Rio Negro, Fernando da Costa de Ataíde Teive, was named Fort of São Fernando do Içá.