Although the recent cleaning of the frescoes in the Hypogeum of the Aurelii in Rome has revived interest, much of the discussion remains concentrated on its mixture of pagan and supposedly "proto-Christian" iconography. This is a pity as there are several beautiful views of large monuments, possibly temple complexes, in Rome. The tomb is just within the Aurelian Walls (AD 271-5), so must pre-date them.
The frescoes should be studied alongside the first century Colle Oppio fresco, but tend to be ignored.
Senators in the third century are still depicted in purple-striped togas.
The tomb was built by Aurelius Felicissimus (235-240 CE) for himself, his virgin sister Aurelia Prima, and his two brothers. Aurelius Felicissimus was a freedman but did well enough that his wife Aurelia Crescentia was honoured as a patroness of Trebula Mutuesca, and he is noted as having been of equestrian rank.
A Felicissimus was in charge of the treasury at Rome at the beginning of Aurelian's reign (Aurelius Victor, De Caesaribus, 35,6; Historia Augusta, Aurelianus, 38.2) - it not impossible that he was the same man, holding a high position towards the end of his life (AD 270), or his son.
Partly because the tomb is on what it now Vatican land, the 'Christian' elements of the iconography are all too often emphasised: it's said the tomb has a cross, not used until a century later in most other places, but in fact this 'cross' might be the bottom of a poorly preserved garland; shepherds have been shown since the Archaic period, and need not be Christian, etc. Its religious design is a contemporary miss-mash of ideas floating around Rome at the time, and since the tomb continued to be used into the next century, some might date from the later period. Most scenes can be given purely pagan interpretations and ... one should note that the tomb was found in 1919 when Orphism was the anti-clerical craze in scholarship (and possibly a modern creation). There were Christians in Rome, but I find it unlikely that such a leading citizen would have openly practised Christianity let alone commissioned a 'Christian' tomb complex others could visit to advertise a still largely illegal religion.