Legends say that the parish was the scene of a massacre of Christians by the Romans and here were discovered the presumed bones of the martyrs of the extinct city of Concordia, a city in ancient Lusitania (according to the Portuguese and Brazilian Encyclopedia). Hence the toponym Assentis derives from “assen”, a derivation of “Loco de Sanctis”. In the neighboring town of Beselga, the ancient city of Besulci, a spiral-shaped stone column was found, which proves the presence of inhabitants during this Roman period. Over the centuries, the parish has gathered a rich heritage, reflected in the main church in honor of Our Lady of Purification, and in the numerous secular chapels in the towns. Also noteworthy are the two crosses, in Assentis and Carvalhal do Pombo.

Until the definitive conquest by the Christians, both the castle and the village were successively destroyed and rebuilt. During the second Fernandine war, in 1372, the then town and its castle were surrounded and partially destroyed by Castilian forces. It was during these events that the story of Gil Pais took place.

Two important courts were held in Torres Novas: those of 1438, held after the death of King Dom Denis of Portugal, and those of 1535, when the marriage contract between Infanta Dona Isabel and Charles V, Emperor of the Holy Roman Empire, was signed.

Regarding the antiquity of Torres Novas, it can be said that here, in the Aroeira cave, the oldest human remains in Portugal were found, namely a 400-year-old Homo heidelberguensis skull. There are many other traces of human presence, from the Paleolithic (such as the caves of Buraca da Moura and Oliveira or Lapa da Bugalheira), through the Neolithic and up to the Iron Age, which are also documented.