Last Supper in Ravenna in the basilica of Sant’Apollinare Nuovo 6th-century mosaic
There is a much earlier depiction of the Last Supper in Ravenna in the basilica of Sant’Apollinare Nuovo (possibly 6th century A.D.). It has everyone on the same side, but with Jesus at one end (extreme left from the viewer’s perspective). Supposedly that was the custom so that the servers could bring the food and set it before people easily.
Last Supper in Ravenna in the basilica of Sant’Apollinare Nuovo 6th-century mosaic