In 1392,
Franciscan friars from
Galicia, under the direction of Friar Diogo Arias, built a monastery on the island. The first fortification on the site dates from this period, meant to protect the river mouth and the religious congregation from pirates, built by order of
King John I. In 1471 the monastery underwent renovation works, with new cells being added and improvements made to its chapel. Later,
Manuel I of Portugal (1495-1521), on a pilgrimage to
Santiago (1502), determined that new renovation works be undertaken, finished in 1512. Likewise, King Philip I of Portugal (1580-1598) promoted new renovations, which adapted it to the use of artillery, an imperative need to face the attacks from English and French privateers. None of these structures have survived.
The 18th century fort The current structure dates from the
War of Restoration (1640-1668). It was built between 1644 and 1652 by the orders of the then Governor of Arms of Minho, Dom Diogo de Lima Nogueira, during the reign of
John IV of Portugal (1640-1656). The dependencies of the monastery and the fort were repaired several times during the 18th century, notably in 1717 after King John V donated 200$000 reis to repair the church, its vaulted ceiling and, in 1767, the construction of new cells, the chapter room and altarpiece. Between 1793 and 1795, the friars left the convent so the renovation works could be concluded. In the same period, in 1765, the fortification was garrisoned by 10 men, and seven bronze cannon. During the
Peninsular War, Ínsua was occupied by Spanish and French troops. Later, with the extinction of the religious orders (1834), the fort was abandoned by the religious community, being garrisoned exclusively by the Portuguese Army. The last governor of the base was appointed in 1909, Major Rodolfo José Gonçalves. It was classified as a National Monument by the Decree of June 16, 1910, published in June 23 of the year. In 1940, it passed from the Ministry of the Navy to the responsibility of the Ministry of Finance. From 1954 to 1957, the complex underwent conservation works, followed by other campaigns from 1967 to 1975, 1984 to 1986 and from 1998 to 2001. In 1990, there was a project by the Polytechnic Institute of Viana do Castelo for the installation of an Advanced Research Center in the marine areas of the coast and River Minho. ==
Programa Revive==