Santa Croce in Gerusalemme:
Chapel of St Helen

Map
Chapel of St Helen, church of Santa Croce in Gerusalemme, Rome
Chapel of St Helen
The Chapel of St Helen, in the church of Santa Croce in Gerusalemme, lies at the original level of the ancient Sessorium, once the residence of Helen, mother of the emperor Constantine (r. 306-37).
Mosaic, vault of the Chapel of St Helen, church of Santa Croce in Gerusalemme, Rome
Christ and the Four Evangelists
The original 5th century mosaics were replaced; their design has been attributed to Melozzo da Forli (1438-94). The mosaics depict Christ and the four Evangelists, St Peter and St Paul, St Helen and Cardinal Caravajal, and Pope St Silvester I. 

The frescoes below the mosaics depict the finding of the True Cross and were painted in 1590 by Niccolò Circignani  (c. 1530 - c.1598), better known as il Pomarancio. 

The statue of St Helen has been adapted from an ancient statue of the goddess Juno, which was unearthed at Ostia Antica. ​
Mosaic of St Helen, Chapel of St Helen, Santa Croce in Gerusalemme, Rome
St Helen & Cardinal Caravajal
Mosaic of St Peter, Chapel of St Helen, Santa Croce in Gerusalemme, Rome
St Peter
Mosaic of St Paul, Chapel of St Helen, Santa Croce in Gerusalemme, Rome
St Paul