Thanks to the excavations carried out during the last years it was possible to set light on the history and aspects of this ancient church of Canosa. It was built on a pre-existing Hellenistic temple of which it uses the podium as the foundation, the blocks of the cell walls and some columns. It was converted from pagan to Christian in the 5th century.

During the second stage, attributed to bishop Sabino, the building was formed by two concentric squares with exedra and bright mosaics on each side (geometrical patterns and themes of heaven symbology).

Between the 7th and the 8th century four pillars in the centre of the building transformed the layout into a cross-plan inserted inside a square. The basilica was then dedicated to Saint Leucio, as a consequence of the devotion to Leucio, the bishop of Brindisi, whose remains were stolen by traesi sailors.

In the 9th century, the construction of a chapel with an apse, along the southern wall, started the burial practice: in fact many tuff sarcophagi and graves were found inside it and nearby.