The first concrete references to Sitges and its lands appear in parchments and other documents in archives from 10^th century, when Barcelona expanded towards the south. In 990 a place called Sitges is already mentioned (translates as silos), and it is that at that time some silos (cavities excavated in the ground to conserve agricultural products). The silos were discovered between the ruins of the old Iberian and Roman towns and this discovery gave the name, first, to the territory and, later, the castle and the town that grew progressively around.

In the first half of the eleventh century there is the first recorded mention of the castles of Sitges, Miralpeix and Campdàsens.  In the twelfth century the monastery of Garraf was established. Each castle had its feudal lord, but during the fourteenth and fifteenth centuries the "Pia Almoina"  (the Seat of Barcelona) obtained (by purchase or inheritance) dominion of these castles and the municipal area of  present-day Sitges.

At that time Sitges was already an important place, thanks to its privileged situation, between Barcelona and Tarragona, and because it was fortified. Their inhabitants went in for viniculture and they were also seafaring traders. From the Greek island of Monembasia they obtained a grape variety called "malvasía", that was to make Sitges very famous in following centuries!

Wars and the plagues seriously affected the population, but by the end of the sixteenth century, the increase in viniculture began and, in especially, the "malvasía" grapes, to such an extent, that Sitges was one of the first places to have an agricultural market.

Sitges had its own fleet of boats dedicated to commerce; an activity that occupied almost half the population. At the same time, the increasing strength of the town had the interest of the feudal lords, and the conflicts began that, little by little, would consolidate the town, a process that did not finish until first half nineteenth century.