In the center of the city of Serres and several metres below the level of the road, stands the resplendent old cathedral of the two Saints Theodore, a large rectangular Basilica. According to tradition it was built on the ruins of an ancient temple. The Cathedral was built in 1224 AD by the Despot of Epirus, Theodoros Angelos Komninos in remembrance of his glorious victory against the Franks, just outside the city.

     The first reference to the Old Cathedral was made in a chrysobull issued by Andronikos the Seniorin 1321 AD. It is described in detail by the rhetorician Theodore Pediasimos from Serres, in his excellent essay “Statement upon the Sanctuary at Feres” (i.e. Serres), 14th century. A plinth inscription on the southern long wall of the Church: testifies that the wall was demolished and rebuiltin 1725. The Saints two Theodore Cathedral is best-known for its marvelous mosaics, the only one of which to survive the fire of 1913 is the one that shows Apostle Andreas and the hands of Apostle Loucas.

     This historic church has been subject to repairs and renovation that resulted in the tranformation of its original form. During the great fire of 1913 the church was almost completely burned. It has been restored by the Archaeological Service.

     The Church fetes the first Saturday of the Lent. On the same day the Holy Skull and the two Saints Theodore icon (i.e.Tyron and Stratilatis) are carried in procession.

     The main Church is a Basilica divided into three aisles, each composed of two series of colonnades.