In this partially preserved relief, the pious son carries his lame father while fleeing the sack of Troy. The son's name is Aeneas; the father's name is Anchises. Aeneas is guided by his mother, the goddess Aphrodite (upper left). Anchises carries a box that holds statues of the ancestral gods of Troy.
The purpose of the facade is clear: to communicate the heritage of Rome and underline provincial loyalty. According to the well-worn story, Aeneas was a Trojan hero (a grandson of its founder, in fact) who escaped the epic battle and eventually settled in Italy. His family, called the Aeneads, gave rise to the Romans. As a community foundation story, it is clever; the Romans reject the status of "newcomers" and claim a place of their own in a deep (and mythic) Mediterranean history.
Mentions of Aeneas are found in Homer's Iliad, but his story is played out fully in Virgil's Aeneid (a masterpiece of Latin literature written prior to the birth of Christ).
The detail pictured above is part of a larger set of reliefs recovered at the site of Aphrodisias, Turkey.