The abandoned village of Congius is located in the countryside of Simaxis, in the Campidano of Oristano. The church of San Teodoro is about 500 m from today's town, along the Oristano-Simaxis-Fordongianus provincial road, where it was transferred, between 1917 and 1924, because of the work to organize the Tirso reservoir. The church is located a short distance from the ruins of the churches of San Nicolò di Mira and dell'Angelo, which in the title recall, like San Teodoro, cults of Eastern Christianity.
In medieval times, the site was called “curtis Sancti Theodori”. From the Latin 'Sanctus Theodorus' derives the agiotoponym 'Santu Eoru', which, deformed into the Sardinian 'Santu Eru', gives the Italian version San Vero. In 1229 the town was registered as 'Sant'Heru de Simayis' or 'Sanctu Eru de Simmakkis'. In the second half of the 16th century Giovanni Francesco Fara cites the “oppidum de S. Hieri”, also calling it “oppidum Congii”. Since 1698, the toponym San Vero Congius has been attested, which indicates the place of the early medieval church dedicated to San Teodoro, a military saint of the Byzantine tradition.
From the photographs taken before the restoration work, which compromised its readability, it can be seen that the building was built with different types of wall equipment: 'opus quadratum', 'opus incertum' and, to a significantly reduced extent, 'opus latericium'.
The restorations have given the structure a homogeneity that is not in keeping with the construction practice with which it was erected and which prevents an archaeological investigation useful for reconstructing building phases and renovations, all the more so since, from a plane-volumetric point of view, the monument, dating between the 6th-7th and the 9th-10th centuries, attests only to the continuity in the Byzantine era of architectural methods that were born in the late antique period.
The church has a cruciform plan, without an apse, with its arms covered with barrel vaults. The headboards O and S house the entrances, but it is not known if they are original. At the intersection of the arms, inside a square tiburium, the dome rises. Between the circular structure of the dome and the square compartment below, a plume connection is made, as in the church of San Giovanni di Sinis, built after the middle of the 6th century.
The frontal arches that generate the barrel vaults of the arms are visible on the outside, as they protrude in an eyebrow at the heads of each arm. This construction method also seems to have been derived from San Giovanni di Sinis, whose façade features barrel vaults in correspondence with the three naves of the longitudinal hall, relating to an extension of the church that could be placed between the 9th and 10th centuries.

History of studies
In 1966, Raffaello Delogu highlighted the importance of the church of San Vero Congius, which seems to reproduce on a smaller scale the planivolumetric configuration of San Saturnino in Cagliari. For Renata Serra, the proposal to date it to the end of the 6th-beginning of the 7th century, expressed in 1966 by Maria Beatrice Geertman Annis, who connected the church of San Teodoro with the sanctuary of Bonarcado, is unacceptable. For the Serra, comparisons must be made with the church of San Giovanni di Assemini, so the dating must be delayed to the 9th-10th century.

Bibliography by
R. Delogu, “Method, Merits and Limits in the Medieval Architecture of Sardinia”, in Proceedings of the XIII Congress on the History of Architecture - Sardinia, I, Rome, 1966, pp. 171-179;
M.B. Geertman Annis, “St. Theodore of Congius (an unknown monument)”, in Proceedings of the XIII Congress on the History of Architecture - Sardinia, I, Rome, 1966, pp. 201-207;
R. Serra, “The Quadridic Church of S. Elia in Nuxis (and several other early medieval documents in Sardinia)”, in Sardinian Studies, XXI, 1968-70, pp. 3, 20-22, 29-30;
P.G. Spanu, Byzantine Sardinia between the 6th and 7th centuries, series “Late Antique and Medieval Mediterranean. Excavations and research”, Oristano, S'Alvure, 1998, p. 154; R. Coroneo-M. Coppola, Byzantine Cruciform Churches of Sardinia, exhibition catalog, Cagliari, 1999, p. 15.
R. Serra, Studies on the Art of Late Antique and Byzantine Sardinia, Nuoro, Poliedro, 2004, pp. 21, 38-41, 43, 46;
R. Coroneo, Romanesque Churches of Sardinia. Tourist-cultural itineraries, Cagliari, AV, 2005, p. 78.

How to get there
You leave the SS 131 at the height of Oristano. After taking the exit for Silì, proceed along the SS 388, cross the town of Simaxis and, after traveling about 2 km, before entering the town of San Vero Congius, turn upwards, on SP 9, to the rural site of Congius, where the church is located, very close to the side of the road.