The early human occupation of the region dates back to prehistoric times, according to archaeological evidence attesting having been successively visited and occupied for centuries by people Greeks, Phoenicians, Carthaginians, Romans, Goths and Moors.
In the context of the Christian Reconquest of the Iberian peninsula, the origin of the village clings to a donation of their domains and other benefits, by D. Afonso Henriques (1112-1185), to a group of crusaders (generically referred to as "Francos"), following the conquest of Lisbon, Sintra, Almada, Palmela and Alenquer, in 1160, when it receiver its first charter.
The beneficiary of the charter of donation would have been D. Alardo, one of the captains who distinguished himself in the Siege of Lisbon (1147).
The classical Portuguese historiography assigns the edification of the castle to D. Alardo himself, but this information lacks in documentary evidence, and even proper archaeological exploration.
On April 11, 1396, Inez Leitão and her husband exchanged a few farms that they had in Cadaval, with Violante Vasques, wife of Afonso Rodrigues Alardo, by the ownership of Vila Verde dos Francos.
There are no information of renovations of the fortification between the late Middle Ages and Modern Age. A report in the eighteenth century states that the castle was already quite ruined.
Perhaps for its advanced state of decay, their remains have not been prioritized by the restoring campaign promoted by the Portuguese Estado Novo. The castle was declared as a public interest building on 18 July 1957.
Little is known of the medieval castle, which is believed should have had an impact on the setting of the Portuguese military architecture, since it was designed and built by a foreigner.
The remnants of the Keep, square-shaped, situated in one of the vertices of the wall, which seems to point to a later chronology, from the Gothic period, since the Romanesque castles had this structure in the yard alone, without contact with the walls.
Similarly, the entrance gate to the castle, which lies lateral to the tower, suggests that Gothic chronology, where the tower defense played active roles access.
In the 1980s, were promoted some consolidation and cleaning works on the walls. Currently still in ruins, and requiring further study.
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