The Casa do Infante is located in the historical centre of Porto, designated World Heritage Site by UNESCO The customshouse was constructed in 1325 by royal decree[1] on top of a Roman villa.

Afonso intended to charge taxes for goods carried by ships navigating the Douro river, thereby reducing the power of the bishop.

[2] At the end of the 14th century, was the first reference to the Portuense Casa da Moeda (House of Coin) during the reign of King D. Fernando I, that allowed dating of the open space in the principal entrance.

[1] The inner courtyard was kept, but the towers were greatly reduced in height, while the front of the building (facing the street) gained two extra storeys, with a large staircase leading to the living quarters in the second floor.

[1] A commemorative inscription, dated 1677,[1] refers to this change: In 1860, the work and construction of the new customshouse in Miragaia, wherein the services were gradually transferred to the new site.

[1] Between 1957 and 1978, the DGEMN Direção-Geral dos Edifícios e Monumentos Nacionais (General Directorate for Buildings and National Monuments) began a series of projects to recuperate and remodel the old customs house.

[1] This included supply and placement of wood on the ceiling and halls of the central patio, concrete staircases, work on the windows, sanitation and drainage of the spaces, as well as complementary restoration of the walls, stone slabs and facades.

[1] Archaeological excavations since 1995 identified a group of structures buried in the entirety of the property, allowing the reconstruction of the medieval organization of the customhouses and "House of Coin", with vestiges of an early Roman construction of grand dimensions, with polychromatic mosaics.