So, I hope you will forgive a brief disclaimer here – I am not an art historian (though I often pretend to be, I am three years into my PhD, and no-one can agree what discipline I belong to) and so all my comments here will be largely informed by personal observations in Christian art, with a background knowledge in some early Christian history. It is entirely possible I am missing large parts of the story here, but I hope that I can begin to offer an answer as to why our representations of biblical figures are how they are, or at least the traditions which informed them.

I want to start by raising a point: your question assumes that early Christian art was aimed to be historical and portray an accurate representation of the gospels. This is not true. Art in the Roman (and late antique) worlds was meant to convey ideologies and meaning. A good example is late antique Roman emperors, who are all bug-eyed beauties, the art is abstract rather than realistic. It did not matter to the audience whether this was an accurate representation of an emperor’s appearance – but rather what ideas this art represented about the emperor’s person. (It is important to note however that the intent behind art varied throughout the Roman period, and many earlier emperors were intended to look more realistic).

So, with this in mind; why were biblical figures presented how they were?

When we think of Jesus, most often we call to mind a man with long hair and beard, and this is in fact the way Christ was represented in a lot of medieval art, which persists until the modern day. However, the earliest representations of Christ do not tally with this understanding. In much of the earliest Christian art, Christ was associated with the “Hellenistic youth”, a beardless ideal of male beauty, with floppy hair and big muscles. The Hellenistic youth was associated heavily with divinity in Graeco-Roman artwork, and many of the more famous deities and heroes fulfilled this archetype: Apollo, Orpheus, Endymion etc. Even eastern deities, such as Mithras, were often portrayed in this way.

Christianity, when assimilated into Roman culture, borrowed a lot of Roman artistic conventions. The Hellenistic youth provided a handy prototype for the representation of Christ, not only was Christ eastern (as the archetype was) but various Graeco-Roman figures were often used as metaphors for Christ (particularly Orpheus, as he went to the underworld and returned). Jesus was frequently portrayed as this ideal: for example, in this late antique sarcophagus from Rome, in which Christ is in the centre.

So, then we get to the disciples. If you look at that sarcophagus, you will realise that Christ is surrounded by several different bearded men – his disciples (although, not all are bearded, there is a variation in the representation of different apostles which I am not qualified to comment on). Whilst Christ was represented with the Hellenistic youth archetype, the apostles were represented as Greek philosophers. Remember, whilst Christ was divine, his apostles were the teachers who spread Christian theology. Rather than a young, beardless and godly figure, the apostles were represented as the Hellenistic philosopher, older and bearded. This prototype would have conveyed the distinctions between the apostles and Christ to the audience: Christ was a god; the apostles were teachers. In early art, there is not too much distinction between the representations of the great Greek thinkers, Socrates, Plato, Aristotle and the apostles. A frequent pose both Christ and the apostles take is in fact the two fingered oratory gesture, which represents educated teaching in the roman tradition.

So, going into the medieval period, we already had an established visual language to communicate ideals about the disciples and their role as teachers – and this language portrayed them as old men. As with Christ, the representations of the disciples were not static. Although not a biblical figure, one of my favourite examples is Jerome, the Christian theologian and ascetic who spent a good period of time living in the desert. Jerome is almost exclusively depicted as an old, bearded man, representing his age and wisdom, but his body is represented in varying ways depending on the ideals of the time. In this unfinished Leonardo Da Vinci image of Jerome from the Vatican, the saint is emaciated (and un-bearded, which is unusual). His old and decrepit body being representative of the extreme asceticism he practiced, and therefore his religious virtue. In this mosaic from the Palatine chapel in Palermo, Jerome has his beard, but he is surprisingly muscular (I am afraid I can’t find a better image, but the Palatine chapel has a lot of buff saints) because even though he was understood to be an old, educated monk, he was also a paragon of religious male virtue – and the ideal man was muscular. It wasn’t “historically” accurate (perhaps, maybe Jerome was a weightlifter in real life, I will never know sadly) but it communicated to the audience ideals about Jerome.

A side note: just because the disciples would have been young during Christ’s ministry, they would not have been young their entire lives. A lot of artwork may also depict them as older, as it would be understood this was when they were preaching themselves.

Sorry for a quite long-winded answer, with a lot of detours, I hope that did something to answer the question, and feel free to ask me anything else if I was unclear! 😊

Also, this is my favourite image of [St. Paul] (http://collections.vam.ac.uk/item/O120942/st-paul-disputing-with-the-plaque-unknown/), because he just looks so silly