The Apse Mosaic at the Basilica of St. John Lateran: Detail, left side
St. Paul, St. Peter, and the Virgin Mary adore the Cross. St. Francis has been sandwiched between Peter and Mary, and the little figure in red is Pope Nicholas IV, who had the mosaic installed in the 13th century.
View the entire mosaic.
Photographed at the site by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.