Castle of Guimarães

In the mid-10th century Countess Mumadona Dias, widow of Count Hermenegildo Gonçalves, founded a monastery in the lower town of Vimaranes — today's Guimarães — and endowed it richly with land, cattle, rents and religious books. The community was exposed twice over, to Muslim raiding from the frontier south of Coimbra and to Norsemen who came up the coast and the navigable rivers in fast ships, so the countess ordered a castle built on the height of Monte Largo above the town: a simple work, probably a tower within an enclosure, dedicated to São Mamede and described in her own charter as newly constructed, to shelter the friars and nuns in case of need.

The castle stayed at the centre of the family's quarrels after her death. Gonçalo Muniuz, a grandson of the countess, attempted to seize town and castle but was blocked by his uncle Gonçalo Mendes, then the family patriarch; Ordonho Ramírez, Mumadona's great-grandson, later took both and bequeathed them to his daughter.

At the end of the 11th century Vimaranes passed, with the County of Portucale, to Henry of Burgundy, and the count and his wife Teresa of León chose the castle as their residence. Henry demolished what survived of Mumadona's century-old work, raised the keep, extended the walled perimeter and opened two entrances — the main gate facing the town on the west and the Porta da Traição on the east.

Their son Afonso Henriques, by tradition born within the castle, is said to have withstood a siege there in 1127 by Alfonso VII of León and Castile, lifted when Egas Moniz pledged his master's vassalage to the besieging king. The following summer, on 24 June 1128, Afonso's forces defeated those of his mother Teresa on the neighbouring field of São Mamede — the victory from which Portuguese independence grew. From 1139, when Portugal broke away from the Kingdom of León, the castle served as official royal residence, and remained so until about 1200.

The shield-shaped castle that stands today is largely the work of King Denis, who remodelled it between the end of the 13th century and the beginning of the 14th, when the keep and residences were rebuilt; the walling of the town itself, whose definitive circuit was begun under Afonso III, was complete before 1322. In that year the alcaide Mem Rodrigues de Vasconcelos, holding for the king, beat off a siege by the Infante Afonso. In 1369 Henry II of Castile invaded Portugal through the Minho, took Braga and encircled Guimarães, but was defeated by the townspeople and by forces loyal to the alcaide Gonçalo Pais de Meira.

During the crisis of 1383–1385 the alcaide Aires Gomes da Silva held the town for Castile and Beatriz; in June 1385 forces loyal to John I besieged and took it. John united the upper and lower towns into a single municipality named Guimarães in 1389, and the two towers flanking the castle's main gate were built on his orders sometime between 1383 and 1433.

Advances in artillery stripped the castle of its defensive purpose from the 15th century. Its buildings housed the municipal jail in the 16th century and a royal hayloft in the 17th, and in 1653 the town's prosecutors petitioned the Cortes that the castle, 'the most sumptuous of the kingdom', was falling into ruin and without care would be ruined completely. Under King Miguel (1828–1834) it served as a political prison, and in 1836 a member of the Patriotic Society of Guimarães urged its demolition so the stone could pave the town's streets — a proposal defeated in the municipal chamber by a single vote, though the Torre de São Bento was pulled down in the middle of the century.

In 1881 the castle was classified a Historic Monument of the First Class, the only one in the Minho, and decrees of 1908 and 1910 made it a National Monument. Restoration begun in 1937 by the national monuments service ended with the castle's re-inauguration on 4 June 1940, during the celebrations of the eighth centenary of Portuguese nationhood. Excavations in the interior in 2004 dated structures to the 10th century; in 2007 the castle was voted one of the Seven Wonders of Portugal, and in 2022 it recorded 302,761 visitors.