This grandiose sculpture monument was created to enclose the wooden throne of St Peter. The four gigantic statues of Doctors of the Church are: St. Ambrose, St. Anthanasius; St. John Chrysostom, and St. Augustine.
The fine alabaster window shows the Holy Spirit as a dove.
St. Helen was the mother of Constantine. She converted to Christianity and performed many acts of charity, including building churches in Rome and in the Holy Land. Legend has it that on a pilgrimage to the Holy Land, St. Helen discovered the True Cross.
Daily masses are held in the left transept (as seen below) at the central altar dedicated to St. Joseph. The schedule is posted at the entrance to the Sacristy. On the left side is the Altar of the Crucifixion of St. Peter, thought to be nearest the spot where the Apostle died in the Circus of Nero.