In Palaeologan times a free cross-shaped church was founded to the east of the citadel of Rentina. The original height is still evident, as a large portion of the dome has survived. The church was erected in the east section of the fortifications, though they had ceased to be effective from as early as the mid-12^th century.

The floor plan is typical for this type of cruciform church. An octagonal dome with a high cylindrical drum rests on four vaults that form a cross; the vaults are in turn supported by a series of rectangular blocks that function as corbels, protruding from the church walls.

There are four windows in the sides of the drum, alternating with niches full of ceramic decoration. The arches and niches are framed by brick arches which support the curved, indented roof cornice . The main structure has four further windows, one in each wall and in the three-sided apse. The walls were built of roughly hewn stones and bricks, most of which derive from older structures in the castle. The ceramoplastic dome decorations resemble those in churches in Thessaloniki and Mount Athos, lending weight to the hypothesis that the church was founded in the first half of the14^th century.

Archaeologists have investigated a group of children's graves by the southwest corner of the church.