The first navigator to land in Portugal was Diogo Leite in 1531, commanded by Martim Afonso de Sousa, who entered the bar of the Gurupi and Turiaçu rivers, commanding two vessels named Princess and Rosa, a fact corroborated by the historians Francisco Adolfo de Varnhagen (Visconde Porto Seguro) and Maurício Martins Meireles.

The location of the Abra and not the arrival of that navigator at the mouth of the Gurupi River as early as 1531 is discussed, since they are quite plausible in stating that he actually arrived in the present lands of the municipality of Viseu, of the foundation of the city of Belém and 103 years before the foundation of Sousa do Caeté (present Bragança, which was founded only in 1634).

The French began to settle in Maranhão around 1594 and remained there until they were expelled and left definitively on November 3, 1615, after being surrounded by troops under the command of Alexandre de Moura.

The first settlement on the bank of the Gurupi River, which was named Vera Cruz, was only definitively founded in April 1627, on the orders of Francisco Coelho de Carvalho, and was composed of Indians and dwellers who were taken from Pará and Maranhão.

In 1655, Father Antônio Vieira founded the Jesuit mission of St. John the Baptist in the Gurupi River (more precisely in the town of Vera Cruz), which remained in that village until 1672, when it was transferred to Caeté.

Although its lands were known from 1531 and received the visit of French and Portuguese in 1613, the city of Viseu was only definitively occupied in Century XVIII, having in 1758, was founded a parish.