Saint John Theristus who was born on 1049 was an Italian Byzantine monk, called Theristus or “Harvester”.
He was of Calabrian lineage, born in Sicily. John's Calabrian mother had been captured by the Saracens and brought to Sicily. He contrived to escape to Calabria while still a child, and there he became a Greek monk.[2] He helped to miraculously harvest a large crop ahead of destructive weather, saving the locals from starvation, and gaining the title attributed to him.[3] There he remained until his death of natural causes, in 1129.
The monastery of San Giovanni Theristis is entitled to him.