Origins and Roman era Archaeological evidence suggests that the area around Arraiolos has been inhabited since at least the late
Neolithic or
Chalcolithic periods, indicating significant human occupation as early as the 4th millennium BCE. Historians believe that during
protohistoric times, the site of the present-day Castle of Arraiolos served as a central habitat. Prehistoric objects were excavated from a
tumulus in Arraiolos at the beginning of the twentieth century. These included a
trapezoid-shaped plaque with
geometric design and three pottery vessels. These are now housed in the
British Museum with similar discoveries also reported in
Vendas Novas. A
Roman settlement may have existed in the area around Arraiolos. Evidence suggests that the Church of Santana do Campo was constructed over the remains of a
Roman temple, with remnants visible in the church structure and nearby constructions, including the southern cemetery wall. A Roman inscription was also found nearby at Herdade da Ravasqueira. This settlement is believed to have corresponded to a
vicus, a small agricultural community that evolved from an indigenous site under Roman influence. Historians have suggested that this settlement may have been called "Calântica." Others trace its origins to
Sabine,
Tusculan, and
Alban settlers who are believed to have arrived in the area before the
Sertorian Wars, led by a figure named Rayeo. This name, "Rayeo," could be the root of "Rayolis," which eventually evolved into Arraiolos.
Middle Ages During the Islamic period, Arabic sources offer few details on the region, aside from the growing importance of Évora from the 10th century onward. In 1165, the area around Arraiolos likely was reconquered by
Gerald the Fearless during the reign of
King Afonso Henriques. The land remained under the control of the Portuguese crown for less than a century.
King Pedro I granted it to Rodrigo Afonso de Sousa, the son of Afonso Dinis, who was the illegitimate son of King Afonso III. After Sousa's death, the land was given to
Álvaro Pires de Castro, the brother of
Inês de Castro and the title of
count of Arraiolos was created. ==Parishes==