Archaeological discoveries reveal that Gondomar has been inhabited since prehistoric times. The area also shows evidence of
Roman occupation, particularly through gold mining activities in the surrounding regions. The name "Gondomar" is often attributed to the
Visigothic king
Gundemar, who is said to have established a couto (ecclesiastical domain) there in 610, although no evidence supports the presence of Visigothic knights in the area. In 1515, during the reign of
King Manuel I, Gondomar was granted its first
foral (charter), which modernized its administrative and fiscal framework as part of the monarch’s broader reforms aimed at centralizing power and updating local taxation systems. These fertile lands were also granted to Margarida de Vilhena, who was awarded various privileges, including income and rents from the territory. In 2011, the
Porto Metro light-rail system reached the areas of Rio Tinto,
Baguim do Monte and Fânzeres. Significant milestones in the 20th century include the establishment of the parish of Baguim do Monte in 1985 and Gondomar's elevation to city status in 1991, followed by Rio Tinto in 1995 and Valbom in 2005. ==Cities and towns==