Found: Spain's earliest ever image of Jesus - The Local:
“We know it dates back to the 4th century, in part because popes in the following centuries ordered all patens to be made out of silver,” Marcelo Castro, head of the Forum MMX excavation project, told The Local.The context provides the function, so this 22 cm glass plate has been identified as a liturgical object. The dig is a very interesting one, and Justin Walsh blogged about it for the Day of Archaeology.
There are a few points I'd like to elaborate on, namely the claim that the popes ordered all plates to be made of silver. Firstly despite the claim of the Donation of Constantine, which has long been shown to be a fake, most popes had little authority outside Rome; some had personal authority, but the concept of the bishops of Rome as popes is a Modern one that did not apply in Late Antiquity.
Glass and silver were both expensive, but silver was more durable. Both continued to be used, but most communities could not afford them and used clay vessels.
This is the earliest certain and dated depiction of him, now in Yale, but from the house-church at Dura Europos. This in turn was the earliest securely dated 'church' because we know the town was destroyed and abandoned after AD 257. The rich archaeological finds are one reason it is sad that the site has now fallen into the hands of ISIS.
The Arians, although later considered heretics, were a force within early Byzantine Christianity; several Emperors were Arian, as were the Ostrogoths who left their mosaics at Ravenna including a beardless Jesus in the Baptistery.
Spain was held from AD 410 by the Visigoths who were also Arian. Arians favoured the interpretation of Jesus being subordinate to God, and the way this is reflected in their art is by showing him as a man without a beard. Mary rarely appears in Arian or Early Byzantine art as she was considered subsidiary at the time.
Since these plates were given out by Emperors as gifts to favoured leaders, and since Spain fell to the enemy not long after this one was given in AD 388, one can assume that either the owner fled or his heirs did not want to advertise a no longer suitable alliance. Art honouring the enemy was often the object of iconoclasm, but metals could be melted down and re-used. Throughout the Medieval period the rich regularly melted down plate to mint coins.
The iconography of the glass plate makes it 4th century. This is an amazing discovery and I can't wait to read the publication.