Remains of Chalcolithic and Bronze Age communities have been found in the area around Sonseca. In the area of El Horquillo, in the Dehesa de Villaverde, bell-shaped and non-bell-shaped ceramic fragments from the late Chalcolithic or transition to the Early Bronze Age have been found.[17] [18].
During the Second Iron Age the area was integrated into the area of Carpetania. These pre-Roman peoples settled on fortified hills, practiced advanced cereal agriculture and sheep farming, and produced turned and hand-turned ceramics. Their culture dominated the region until the arrival of Rome in 179 BC. c.
After the conquest of Carpetania in the year 179 BC. C., the Sonseca area was incorporated into the Roman sphere, being integrated first into the Tarraconensis province and, after Diocletian's reform in the year 298, into Cartaginensis, in the municipium of Toletum.[19] The area had a network of secondary branches that linked with the Toletum–Corduba and Toletum–Emerita Augusta roads, facilitating the departure of products such as cereal, oil and wool to the markets of the Tagus Valley. The local economy was transformed with intensive cereal agriculture and sheep farming, supported by hydraulic infrastructure that ensured irrigation.[20].
Sonseca has also been related to the Roman toponym Vicius Viciarius, which would indicate the existence of a settlement or vicus of a rural nature in the area where the urban center is currently located in Roman times.[21] In the area of La Mezquitilla, in the homonymous meadow, remains of a large rustic villa have been found that of probable Neolithic origin, was active as a Roman villa between the High and Low Empire, organized as a large estate with residential area, granaries and winepresses for the production of wine, oil and grain. Among the recovered materials are masonry walls, fragments of terra sigillata, amphorae and common ceramics, as well as denarii from Hadrian's time. A stone inscription stands out with the text: “Bandu/e · It(obrigo ?) · Vic/iesi · ex / vote · Ti/omace · pos(uit)”, interpreted as “Tiomece put this votive offering to Bándula”. Added to this are the nearby Alcantarilla and Vallehermoso dams, infrastructures intended for hydraulic regulation and that supplied the city of Toletum and La Mezquitilla.[22].
The Berber Táriq ibn Ziyad, on his way to dominate Toledo, entered through Marjaliza and continued through Arisgotas, Casalgordo, Sonseca, Layos and Argés, crossing the Tagus River and reaching the city.[23].
After the Muslim invasion of the peninsula, Sonseca was populated by Mozarabs and Arabs, who built the Tolanca Tower. Since the Middle Ages it belonged to the municipal lordship of the city, and residents and monasteries of Toledo had numerous properties in the town, such as the monastery of Santo Domingo el Real.
In June 1212, the Christian forces of Alfonso VIII left Toledo on their way to the Battle of Las Navas de Tolosa, through the current Cañada de las Merinas), passing through Ajofrín, Sonseca, Arisgotas and Marjaliza, after which they headed towards the Algodor River.
In the year 1399, we know that it was linked to Casalgordo and Arisgotas, forming a single municipality, as we see in a letter from Enrique III, where reference is made to "the council of Sonseca e Arisgotas e Casalgordo.".
In 1629 it acquired the title of town "Villa (population)"), after incurring a significant amount of debt, achieving the independence of Toledo, and this is how it came under royal jurisdiction.
Not being able to meet these payments, in 1640 the inhabitants of the town completed the sale of the lordship, jurisdiction and vassalage with the Portuguese Duarte Fernández Acosta, this being the first lord of the Sonseca lordship. His son Álvaro would take possession of the town in 1641.
It is described in volume fourteen of the Geographical-statistical-historical dictionary of Spain and its overseas possessions by Pascual Madoz as follows:
Casalgordo, which until then had been an independent municipality, became part of Arisgotas in 1845, and was finally incorporated into Sonseca in 1853, at which point the municipality was renamed "Sonseca con Casalgordo", a name that lasted well into the century.[24][25][26].
During these centuries, and especially in the century, its textile industry developed, during the century the first marzipan workshops were installed, and in the 1950s the enterprising businessman Antonio Moraleda gave rise to the widespread furniture industry of Sonseca, main industrial sectors of the development of the municipality.