Six Apostles

Fresco
Basilica of St. Paul Outside the Walls

The names of the apostles are given in the framing strip below their portraits, although the strip has peeled away below the two in the center and left only the letter "S" for the third figure from the right. Left to right, they are Andrew (long cross), John (beardless youth), Bartholomew (flaying knife), Thomas (uncertain – attribute here is a spear), Jude (spear), and Matthias (maquette of a church).

I have no information on the date of this fresco, but some of the iconography suggests a date in the first centuries of the second millenium. St. Andrew's holds a Latin cross, which artists often put in his hands until about the 15th century, when the X-shaped "cross saltire" prevailed. I have not seen any images of Andrew with a cross from the first millenium. (Indeed, any use of attributes is much more prominent in the second millenium.) Another clue for dating is the church maquette cradled in the arm of St. Matthias on the far right. The church appears to be Romanesque in design, tall and thin with a square campanile. Thus my guess for the date would be the 11th or 12th century.

If this is correct, the fresco would be an early example of the iconographic type in which a hymn or prayer appears in sections on scrolls held by the apostles. Unfortunately, the writing on these scrolls has faded so much that the text cannot be identified.

This image in full resolution

More of Saint Andrew
More of Saint John the Evangelist
More of Saint Bartholomew
More of Saint Thomas
More of Saint Jude Thaddeus
More of Saint Matthias

Source: Photographed at the basilica by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.