The green glass paten, the plate which holds the Holy Eucharist in churches, is the earliest depiction of Jesus found in Spain and is in excellent condition compared to similar pieces discovered around Europe.
“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 team of archaeologists have so far managed to find 81 percent of the paten at the site of a religious building in Cástulo, an ancient Iberian town in the province of Jaén, Andalusia.
Measuring 22 centimetres in diameter, it shows three beardless men with short hair and halos over their heads.
According to Castro, the figures are Jesus and the apostles Paul and Peter as depicted in Christ in Majesty, an early Christian art form which copied Roman and Byzantine styles.
The Forum MMX team have been able to establish the paten was made in the 300s thanks to coins and ceramic objects found at the same site.
“We were wary about presenting the paten as a 4th century piece in case it clashed with previous studies into the chronology of Christianity in Spain,” Castro explained.
But their estimates coincide with the rule of Constantine, the first Roman emperor to claim conversion to Christianity, who also ensured the religion's clandestine followers were no longer persecuted.
The paten was put on display on Wedneday at the Archaeological Museum of Linares (Jaén), alongside other ancient pieces such as a mosaic of Cupid (Mosaico de los Amores), unearthed in 2012 and named as one of the discoveries of the year by National Geographic.