This one is particularly intriguing. According to “The Eternal Letter,” it’s mentioned that “The distinctive Damasian capital letter, used for tables memorializing Christian martyrs, was designed by Furius Dionysius Filocalus, secretary to Pope Damasus I (reigned 366–384).”
I came across them in the Basilica S. Sebastiano Fuori le Mura (which, by the way, is located on Via Appia Antica) and inside the adjacent early Christian catacombs. The plate in the photo dates back to the 4th century.
Take a look at the details! The serifs have such a playful shape, and the bowl and leg of the “R” are not connected. There’s almost no contrast in the bowls of “R”, “P”, “B”, and of course, the ligatures are beautifully crafted. One could contemplate them for quite a while. In terms of proportions, these letters don’t exhibit as noticeable a difference as the Roman capitals do.
Basilica S. Sebastiano Fuori le Mura, Via Appia Antica, Rome.