Laredo became the main harbour of the region because a part of the Spanish Royal Army moored here.
The Catholic Kings, their daughter Jane of Castile, Charles V, (Jane´s son), and Philip II (son of Charles V) chose the port of Laredo to set out their trips outside Spain.
Laredo got to be the only maritime city, from the Basque Country to Galicia, which was prepared to perform honour shots during arrivals and departures of royal boats.
In 1556, the arrival of Charles V at Laredo coincided with a period of urban and demographic growth. At that time, local authorities were striving to control people, banned books, and goods traffic, the kinds of such goods including legal, smuggled (“descaminadas”), and prohibited (“vedadas”) merchandise. It is worth recalling here that gold, silver, and weapons were regarded as prohibited goods. Moreover, local authorities must also keep a close watch on the coast due to the continuous threat of enemies´ arrival.
The markets were the main point of sale for the products that passed through Laredo: the "Mercado de la Plaza de la Villa", the "Mercado de las Piras del Pescado", the "Mercado del Azogue" and the "Mercado del Cementerio".
The Market of the Plaza de la Villa: Here the fish was always sold wholesale. In the sixteenth century this square was already socially booming and many important families of the Villa began to build their tower houses here. The fishermen sold their catches, fresh or wholesale. It was connected by the river Bario to the Plaza de las Pilas del Pescado.
The Plaza de las Pilas del Pescado: Here the best fish were washed in a fountain, the fish was smoked and the escabeche was made. Justice was given in this square, since it had gallows and pillory. The scaffold was replaced by a scaffold.
The Azogue Market: Here, the "regatonas" sold or exchanged their merchandise. Many times it was "el quiñón", the part of the captures that belonged to their husbands for having participated in the working day at sea. Here it was the workshops of artisans, blacksmiths, basket makers, carpenters and other apothecary shops were centralized. The craftsmen removed their merchandise with planks to the outside, and under the arcades the merchandise was sold. To improve the place, the Council ordered the construction of a fountain.
The Cemetery Market: The members of the Town Council met after mass, in the cemetery under an ash tree, to make decisions concerning the town. It was also the place where the processions were held to ask for not having mists during the days fishing in the sea. Being the enclosure of the Church of Santa Maria, still walled from the thirteenth century, the open space of the cemetery became a good option to meet in an open space, sell highly regulated merchandise, with the ability to be controlled by the bishop and by the Council. The goods exchanged here were those brought by the "mulateros" of Castile; wheat, bread, wine and other food as important as they could never miss in the Villa de Laredo